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PART IV SUPPLEMENTS TO THE SERIES E RECOMMENDATIONS AND TRAFFIC ENGINEERING |
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MONTAGE: PAGE PAIRE = PAGE BLANCHE 2 ^
TABLE OF THE ERLANG FORMULA
Table of the
Erlang loss formula
(Erlang No. 1 formula, also called Erlang B formula)
Loss probabilities : 1%, 3%, 5%, 7%.
Let p = the loss probability y = the traffic offered (in Erlangs) n = the number of circuits
-v'2P' -v'3p' Formula: E 1, n (y ) = p = $$2o @ { fIy~~n } over { fIn~! } @ $$3u1 + [Formula Deleted] @ { fIy~2 } over { ! } @ + @ { fIy~~n } over { fIn~! } @ $$3e
H.T. [T1.1]
Unable to convert table Table 1 [T1.1], p.
Fascicle II.3 -- Suppl. No. 1 3
|
RELATION |
CURVES SHOWING THE AND THE NUMBER OF CIRCUITS REQUIRED |
|
|
4 Fascicle II.3 -- Suppl. No. 2 |
Figure 1, p. |
Figure 2, p. Supplement No. 3
INFORMATION ON TRAFFIC ROUTING IN THE INTERNATIONAL NETWORK
(Results from study in 1973-1976 of Question 11/XIII
concerning actual connections of international telephone calls
(For the text of this Supplement, see Supplement No. 7,
Volume II.2, Orange Book , Geneva, 1976)
Fascicle II.3 -- Suppl. No. 3 5
USE OF COMPUTERS FOR NETWORK PLANNING AND CIRCUIT
GROUP DIMENSIONING
(For the text of this Supplement, see Supplement No. 8,
Volume II.2, Orange Book , Geneva, 1976)
TELETRAFFIC IMPLICATIONS FOR INTERNATIONAL SWITCHING AND
OPERATIONAL | PROCEDURES RESULTING FROM A FAILURE OF A
TRANSMISSION FACILITY
1 Very considerable changes have occurred in the international network over the past decade. These changes have arisen mainly from:
|
-- -- -- -- |
the growth in the number of long-distance routes; the growth in the number of circuits forming individual long-distance routes; the world-wide introduction of international automatic operation; technological developments associated with all aspects of the international network: switching unit |
design, transmission facility design, and routing and operational strategies;
-- the integration into the international automatic service of the more isolated geographical areas and of centres having low-capacity international switching units.
2 The resultant multiplicity of circumstances and situations arising within the international network is now such that it is no longer possible to specify one single criterion for initiating corrective action to counter the loss of a transmission facility. Indeed, the failure of the whole, or part, of a transmission facility may manifest itself in a different manner to each of several Administrations affected by the failure.
3 Among the many aspects of international switching and operational procedures which can influence the degree of curtailment of service arising from a transmission-facility failure, i.e. which can reduce the ability of part of the international network to carry its designed traffic load successfully, the following are specifically stressed (their order has no particular significance):
-- the introduction of fully automatic international operation, which means that the control of the network, formerly completely operator -controlled, now depends directly on subscribers' habits;
-- the number of routes that could be affected by failure and their proportion of the total routes on the switching unit to which they are directly connected: the range can be from one whole route to a few circuits in each of many routes, depending on the method of allocating circuits to transmission facilities;
-- the influence of any route, for which no alternative transmission facility exists, on the performance of the international switching unit to which it is connected;
6 Fascicle II.3 -- Suppl. No. 5
-- the effect on the grade of service of the switching unit itself due to the loss of a complete route or routes, or parts of several routes, directly connected to it;
-- the methods of limiting the effect of failure on service by action within the switching unit or at preceding international or national switching unit, e.g. by code blocking or recorded announcements;
Fascicle II.3 -- Suppl. No. 5 7
|
-- -- -- -- |
the cause of the failure, and thus the possible restoration time, relative to the 24-hour traffic profile; the effect of a failure on overflow and automatic alternative routing strategies ; the use of diversity of international switching units; the use of diversity of international transmission facilities. |
4 Attention is also drawn to four major factors of maintaining continuity of service:
|
-- -- -- -- |
reliability , diversity, network management , and any redundancy specifically provided to allow restoration of service. |
5 Clearly, no practical transmission facility provided will give 100 per cent reliability, so it is inevitable that the other three factors will be involved to varying degrees in maintaining service. The interaction of these four factors will depend largely on the emphasis placed upon each of them by each Administration, thus reinforcing the view that the degree of corrective action that can be taken will depend considerably upon the investment policy (in materials and equipment) and forward-planning objectives of individual Administrations.
6 With respect to diversity, it is recommended that Administrations give consideration to the provision of an adequate number of paths for a particular route, with an adequate level of independence between the paths. Such independence could reduce the effect of a breakdown or other adverse event by confining it, as far as possible, to only one of the paths used by that route.
7 For the further assistance of Administrations in their study of those teletraffic aspects of international switching and operational procedure which influence the degree of curtailment of service and which arise from a transmission facility failure, these factors are included in Question 23/II related to continuity of service, accepted for study during the 1985-1988 Study Period.
TERMS AND DEFINITIONS FOR QUALITY OF SERVICE, NETWORK PERFORMANCE,
DEPENDABILITY AND TRAFFICABILITY STUDIES
CONTENTS
|
PART I -- Dependability Vocabulary 1 Introduction 2 Related Recommendations 3 Basic concepts 8 Fascicle II.3 -- Suppl. No. 6 |
|
4 5 |
Performances Events and states 5.1 Defects 5.2 Failures 5.3 Faults 5.4 Errors and |
mistakes |
|
|
5.5 States |
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Fascicle II.3 -- Suppl. No. 6 9 |
|
6 7 |
Maintenance Time concepts 7.1 Maintenance related times 7.2 Item state related times 7.3 Time concepts related to reliability |
reliability performance |
|
|
8 |
Measures of performances 8.1 Availability performance 8.2 Reliability performance 8.3 Maintainability performance 8.4 Maintenance support performance |
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|
9 |
Test, data, design and analysis 9.1 Test concepts 9.2 Data concepts 9.3 Design concepts 9.4 Analysis concepts 9.5 Improvement processes |
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10 |
Measure modifiers |
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PART II -- Statistical vocabulary 1 Introduction 2 Terms and definitions Annex A: Alphabetical list of definitions contained in this Supplement Annex B: Relations between defect, failure and fault concepts Annex C: List of recommended symbols and abbreviations |
PART I
Dependability Vocabulary
A consistent set of terms and definitions is required for the development and use of the various Recommendations addressing aspects relating the specifications, planning, data collection, analysis and evaluation of the dependability, including availability performance, reliability performance, maintainability performance and maintenance support performance. These needs address the whole range of operational and maintenance aspects as applicable to telecommunication networks, exchanges, transmission routes and channels, etc., independent of the types of services 10 Fascicle II.3 -- Suppl. No. 6
supported, including aspects of providing the necessary maintenance.
The vocabulary provided by this Supplement is also of importance in the handling of concepts related to quality of service and network performance. The conceptual relationships between quality of service and network performance to dependability and other item-related performances is shown in Figure 1. Further information on these performances is found in Recommendation E.800.
The vocabulary also provides the necessary linking to the performances of components and building blocks (hardware and software) of networks at any level of indenture (ref. definition 6019).
Fascicle II.3 -- Suppl. No. 6 11
Figure 1, p.
For the quantitative application and determination of measures, the terms and definitions of Part II also need to be consulted.
E.600 -- Terms and definitions of traffic engineering
E.800 -- Quality of service and dependability vocabulary.
3001 item; entity
F: entite;´ individu
S: elemento; entidad; item´
Any part, device, subsystem, functional unit, equipment or system that can be individually considered.
Note 1 -- An item | ay consist of hardware, software or both, and may also include people, e.g. operators in a telephone operator system.
Note 2 -- In French, the term entite´ | eplaces the term dispositif | reviously used in this meaning, because the term dispositif is also the common equivalent for the English term ``device''.
12 Fascicle II.3 -- Suppl. No. 6
Note 3 -- In French, the term individu | s used mainly in statistics.
Fascicle II.3 -- Suppl. No. 6 13
3002 repaired item
F: entite´ repar´ ee´
|
S: elemento reparado A repairable item | hich is in fact repaired after a failure . |
||
|
3003 |
non-repaired item F: entite´ non repar´ ee´ S: elemento no reparado An item | hich is not repaired after a failure . Note -- A non-repaired item | ay be repairable or not. |
|
|
3005 |
required function F: fonction requise S: funcion´ requerida A function or a combination of functions of an item | hich is considered necessary for the provisioning of a given |
service .
3006 functional mode
F: mode de fonctionnement
|
S: modo de funcionamiento A subset of the whole set of possible functions of an item . |
|||
|
3007 |
instant of time F: instant S: instante (de tiempo) A single point on a time scale. Note -- The time scale may be continuous as calendar time, or discrete, e.g. number of use cycles. |
||
|
3008 |
time interval F: intervalle de temps S: intervalo de tiempo All instants of time | etween two given instants of time . |
||
|
3009 14 |
(time) duration Fascicle II.3 -- Suppl. No. 6 |
F: duree´
|
S: duracion´ The difference between the end points of a time interval . |
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|
3010 |
accumulated time F: duree´ cumulee´ S: tiempo acumulado The sum of time durations | haracterized by given conditions over a given time interval . Fascicle II.3 -- Suppl. No. |
6 15 |
3011 measure (as applied in the study of reliability performance and related areas)
F: caracteristique´ (probabilite);´ mesure (en fiabilite´ et domaines connexes)
|
S: medida (aplicada en estudios de fiabilidad y de aspectos conexos) A function or quantity used to describe a random variable | r a random process . Note -- For a random variable , examples of measures 3012 operation |
F: exploitation
S: explotacion;´ operacion´
Combination of all technical and corresponding administrative actions intended to allow an item | to perform a required function , recognizing necessary adaptation to changes in external conditions.
|
Note -- By external conditions are understood, for example, service demand and environmental conditions. |
||
|
3013 |
modification (of an item) F: modification (d'une entite)´ S: modificacion´ (de un elemento) The combination of all technical and corresponding administrative actions intended to alter the capability of an |
item by changing, adding or deleting one or more required functions .
4001 dependability
F: s| rete´ de fonctionnement
S: seguridad de funcionamiento
The collective term used to describe the availability performance | nd its influencing factors: reliability performance, maintainability performance and maintenance support performance .
|
Note -- Dependability is used only for general descriptions in non-quantitative terms. |
||
|
4002 |
availability performance F: disponibilite´ S: disponibilidad The ability of an item | o be in a state to perform a required function | t a given instant of time or at any instant |
of time within a given time interval , assuming that the external resources, if required, are provided.
Note 1 -- This ability depends on the combined aspects of the reliability performance , the maintainability performance and the maintenance support performance of an item .
16 Fascicle II.3 -- Suppl. No. 6
Note 2 -- In the definition of the item | he external resources required must be delineated.
Note 3 -- The term availability | s used as an availability performance measure .
Note 4 -- Warning: the term availability has occasionally been used in connection with the term item , but with an implied meaning of item being entirely different from that of this Supplement.
Fascicle II.3 -- Suppl. No. 6 17
4003 reliability performance
F: fiabilite´
S: fiabilidad
The ability of an item | o perform a required function | nder given conditions for a given time interval .
Note 1 -- It is generally assumed that the item | s in a state to perform this required function at the beginning of the time interval .
|
Note 2 -- The term reliability | s used as a measure of reliability performance . |
||
|
4004 |
maintainability performance F: maintenabilite´ S: mantenibilidad The ability of an item | nder stated conditions of use, to be retained in, or restored to, a state in which it can |
perform a required
|
function , when maintenance is performed under given conditions and using stated procedures and resources. Note -- The term maintainability | s used as a measure 4005 maintenance support performance |
F: logistique de maintenance
S: logistica´ de mantenimiento
The ability of a maintenance organization, under given conditions, to provide upon demand the resources required to maintain an item , under a given maintenance policy .
Note -- The given conditions are related to the item | tself and to the conditions under which the item is used and maintained.
4006 durability
F: durabilite´
S: durabilidad
The ability of an item | o remain in a condition where it can perform a required function under stated conditions of use and maintenance until a limiting state is reached.
Note -- A limiting state of an item | ay be characterized by the end of the useful life , unsuitability for any economic or technological reasons, etc.
5.1 Defects
18 Fascicle II.3 -- Suppl. No. 6
5101 defect
F: defaut´
|
S: defecto Any departure of a characteristic of an item | rom requirements. Note 1 -- The requirements may or may not be expressed in the form of a specification. Note 2 -- A defect may or may not affect the ability of an item | o perform a required function . Fascicle II.3 -- Suppl. No. 6 |
19 |
5102 bug
F: erreur de programmation; bogue
|
S: error de programacion´ A software defect | aused by a mistake . |
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|
5103 |
critical defect F: defaut´ critique S: defecto critico´ A defect | hat is assessed likely to result in injury to persons or significant material damage. |
||
|
5104 |
non-critical defect F: defaut´ non critique S: defecto no critico´ A defect | ther than a critical defect . |
||
|
5105 |
major defect F: defaut´ majeur S: defecto mayor A defect | hat is likely to result in a failure | r to reduce materially the usability of the |
item for its intended |
purpose.
5106 minor defect; imperfection
F: defaut´ mineur; imperfection
|
S: defecto menor; imperfeccion´ A defect other than a major defect . |
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|
5107 |
defective; defective item F: defectueux;´ entite´ defectueuse´ S: defectuoso; elemento defectuoso An item | hich contains one or more defects . |
||
|
5108 |
critical defective item F: defectueux´ critique S: elemento defectuoso critico´ |
||
|
20 |
Fascicle II.3 -- Suppl. No. 6 |
|
5109 |
An item | hich contains one or more critical defect . major defective item F: defectueux´ majeur S: elemento defectuoso mayor An item | which contains one or more major defects . |
||
|
5110 |
minor defective item F: defectueux´ mineur S: elemento defectuoso menor An item | hich contains one or more minor defects | ut no major defects . Fascicle |
II.3 -- Suppl. No. 6 21 |
5111 design defect
F: defaut´ de conception
|
S: defecto de disen~ o |
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|
A defect | ue to an inadequate design of an item . |
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|
5112 |
manufacturing defect F: defaut´ de fabrication S: defecto de fabricacion´ A defect | ue to nonconformance in manufacture |
to the design of an item or to specified manufacturing |
processes.
|
5.2 5201 |
Failures failure |
||||
|
F: S: |
defaillance´ fallo |
|
The termination of the ability of an item | o perform a required function . Note -- After failure | he item | as a fault. |
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|
5202 |
critical failure F: defaillance´ critique S: fallo critico´ A failure | hich is assessed likely to result in injury to persons or significant material damage. |
||
|
5203 |
non-critical failure F: defaillance´ non critique S: fallo no critico´ A failure | ther than a critical failure . |
||
|
5204 |
misuse failure F: defaillance´ par mauvaise utilisation S: fallo por uso incorrecto A failure | ue to induced stresses during use which are beyond the stated capabilities of the item . |
||
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22 |
Fascicle II.3 -- Suppl. No. 6 |
5205 mishandling failure
F: defaillance´ par fausse manoeuvre
|
S: fallo por manejo incorrecto A failure | aused by incorrect handling or lack of care of the item |
||
|
5206 |
(inherent) weakness failure F: defaillance´ par fragilite´ (inherente)´ S: fallo por fragilidad (inherente) A failure | ue to a weakness inherent in the item | tself when subjected to stresses within the stated capabilities |
of the item
Fascicle II.3 -- Suppl. No. 6 23
5207 design failure
F: defaillance´ de conception
|
S: fallo de disen~ o |
||
|
A failure | ue to a design defect . |
||
|
5208 |
manufacturing failure F: defaillance´ de fabrication S: fallo de fabricacion´ A failure | ue to a manufacturing defect . |
|
|
5209 |
ageing failure; wearout failure F: defaillance´ par vieillissement; defaillance´ par usure S: fallo por envejecimiento; fallo por desgaste A failure | hose probability of occurrence increases with the passage of time, as a result of processes inherent in |
the item .
5210 sudden failure
F: defaillance´ soudaine
|
S: fallo repentino A failure | hat could not be anticipated by prior examination or monitoring. |
||
|
5211 |
gradual failure; degradation failure; drift failure F: defaillance´ progressive; degradation;´ defaillance´ par derive´ S: fallo gradual; fallo por degradacion;´ fallo por deriva A failure | ue to a gradual change in time of given characteristics of an item and that could be anticipated by prior |
examination or monitoring.
|
Note -- A gradual failure | an sometimes be avoided by preventive maintenance . |
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|
5212 |
cataleptic failure; catastrophic failure (deprecated) F: defaillance´ cataleptique S: fallo cataleptico;´ fallo catastrofico´ | (desaconsejado) A sudden failure | hich results in a complete fault . |
||
|
5213 24 |
relevant failure Fascicle II.3 -- Suppl. No. 6 |
S: fallo pertinente; fallo relevante
A failure | o be included in interpreting test or operational results or in calculating the value of a reliability performance measure .
Note -- The criteria for the inclusion should be stated.
|
5214 F: |
non-relevant failure defaillance´ non pertinente; defaillance´ |
a ne pas prendre en compte |
S: fallo no pertinente; fallo irrelevante
A failure | o be excluded in interpreting test or operational results or in calculating the value of a reliability performance measure
Note -- The criteria for the exclusion should be stated.
Fascicle II.3 -- Suppl. No. 6 25
5215 primary failure
F: defaillance´ primaire
|
S: fallo primario A failure | f an item , not caused either directly or indirectly by the failure or the fault of another item . |
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|
5216 |
secondary failure F: defaillance´ secondaire S: fallo secundario A failure | f an item , caused either directly or indirectly by the failure | r the fault of another item . |
|
|
5217 |
failure cause F: cause de defaillance´ S: causa de fallo The circumstances during design, manufacture or use which have led to a failure . |
|
|
5218 |
failure mechanism F: mecanisme´ de defaillance´ S: mecanismo de fallo The physical, chemical or other process which has led to a failure . |
|
|
5219 |
systematic failure; reproducible failure; deterministic failure F: defaillance´ systematique;´ defaillance´ reproductible S: fallo sistematico;´ fallo reproducible; fallo deterministico´ A failure | elated in a deterministic way to a certain cause, which can only be eliminated by a modification of the |
design or manufacturing process, operational procedures, documentation or other relevant factors.
|
Note 1 -- Corrective maintenance | ithout modification will usually not eliminate the failure cause . Note 2 -- A systematic failure | an be induced at will by simulating the failure cause . |
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|
5.3 5301 |
Faults fault F: panne; derangement´ S: averia´ |
||
|
26 |
Fascicle II.3 -- Suppl. No. 6 |
The inability of an item | o perform a required function , excluding that inability due to preventive maintenance , lack of external resources or planned actions.
Note -- A fault | s often the result of a failure
| f the item itself, but may exist without prior failure .
5302 critical fault
F: panne critique
S: averia´ critica´
A fault | hich is assessed likely to result in injury to persons or significant damage to material.
Fascicle II.3 -- Suppl. No. 6 27
5303 non-critical fault
F: panne non critique
|
S: averia´ no critica´ A fault , other than a critical fault . |
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|
5304 |
major fault F: panne majeure S: averia´ mayor A fault | hich affects a function considered to be of major importance. |
|
|
5305 |
minor fault F: panne mineure S: averia´ menor A fault | ther than a major fault . |
|
|
5306 |
misuse fault F: panne par mauvaise utilisation S: averia´ por uso incorrecto A fault | ue to induced stresses during use which are beyond the stated capabilities of the item . |
|
|
5307 |
mishandling fault F: panne par fausse manoeuvre S: averia´ por manejo incorrecto A fault | aused by incorrect handling or lack of care of the item . |
|
|
5308 |
(inherent) weakness fault F: panne par fragilite´ (inherente)´ S: averia´ por fragilidad (inherente) A fault | ue to a weakness inherent in the item | tself when subjected to stresses within the stated capabilities of |
the item
5309 design fault
F: panne de conception
S: averia´ de disen~ o
28 Fascicle II.3 -- Suppl. No. 6
|
5310 |
A fault | ue to a design defect . manufacturing fault F: panne de fabrication S: averia´ de fabricacion´ A fault | ue to a manufacturing defect . |
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|
5311 |
ageing fault; wearout fault F: panne par vieillissement; panne par usure |
usure |
|
|
S: averia´ por envejecimiento; averia´ por A fault | esulting from an ageing failure . |
desgaste |
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|
Fascicle II.3 -- Suppl. No. 6 29 |
5312 programme-sensitive fault
F: panne mise en evidence´ par le programme
S: averia´ dependiente del programa
|
A fault | hat is revealed as a result of the execution of some particular sequence of instructions. |
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|
5313 |
data-sensitive fault F: panne mise en evidence´ par les donnees´ S: averia´ dependiente de los datos A fault | hat is revealed as a result of the processing of a particular pattern of data. |
|
|
5314 |
complete fault; function preventing fault |
|
S: averia´ completa A fault | haracterized by complete inability to perform all required functions of an item . Note -- The criteria for a complete fault | ave to be stated. |
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|
5315 |
partial fault F: panne partielle S: averia´ parcial A fault | f an item | ther than a complete fault . |
||
|
5316 |
persistent fault; permanent fault; solid fault F: panne permanente S: averia´ permanente A fault | f an item | hat persists until an action of corrective maintenance is performed. |
||
|
5317 |
intermittent fault; volatile fault; transient fault F: panne intermittente; panne temporaire S: averia´ intermitente; averia´ transitoria A fault of an item | hich persists for a limited time duration |
| ollowing which the item recovers the ability to perform a required
function without being subjected to any action of corrective maintenance
Note -- Such a fault is often recurrent.
30 Fascicle II.3 -- Suppl. No. 6
5318 determinate fault
F: panne franche
S: averia´ clara; averia´ determinable
For an item , which produces a response as a result of an action, a fault for which the response is the same for all actions.
5319 indeterminate fault
F: panne indetermin´ ee´
S: averia´ indeterminable
For an item , which produces a response as a result of an action, a fault such that the error affecting the response depends on the action applied.
Note -- An example would be a data-sensitive fault .
Fascicle II.3 -- Suppl. No. 6 31
5320 latent fault
F: panne latente
|
S: averia´ latente An existing fault | hat has not yet been recognized. |
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|
5321 |
systematic fault F: panne systematique´ S: averia´ sistematica´ A fault | esulting from a systematic failure . |
|
|
5322 |
fault mode; failure mode (deprecated) F: mode de panne; mode de defaillance´ | (terme deconseill´ e)´ S: modo de averia;´ modo de fallo | (desaconsejado) One of the possible states of a faulty item , for a given required function . |
|
|
5323 |
faulty F: en panne S: averiado Property of having a fault . |
|
|
5.4 5401 |
Errors and mistakes error F: erreur S: error A discrepancy between a computed, observed or measured value or condition and the true, specified or |
theoretically correct value or condition.
|
Note -- An error | an be caused by a faulty item , e.g. a computing error | ade by a faulty computer equipment. |
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|
5402 |
execution error; generated error F: erreur d'execution´ S: error de ejecucion´ Error | roduced during the operation of a faulty item . |
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|
32 |
Fascicle II.3 -- Suppl. No. 6 |
5403 interaction error (man-machine)
F: erreur d'interaction | (homme-machine)
|
S: error de interaccion´ | (hombre-maquina)´ An error | n the response of an item | aused by a mistake 5404 propagated error |
F: erreur propagee´
|
S: error propagado An error | n the response to erroneous data input to a non-faulty item . |
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|
5405 |
mistake; error (deprecated in this sense) F: erreur (humaine); faute S: equivocacion;´ error | (desaconsejado en este sentido) A human action that produces an unintended result. Fascicle |
II.3 -- Suppl. No. 6 33 |
|
5.5 |
Item related states | see also Figure 2) |
Figure 2, p. |
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|
5501 |
operating state |
|||||
|
F: S: |
(etat´ de) fonctionnement estado de funcionamiento; estado operacional |
|
The state when an item | s performing a required function . |
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|
5502 |
non-operating state F: (etat´ de) non-fonctionnement S: estado de no funcionamiento The state when an item | s not performing a required function . |
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|
5503 |
standby state F: (etat´ d') attente S: estado de espera (en reserva) A non-operating up state | uring the required time . |
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|
5504 |
idle state; free state F: etat´ vacant; etat´ libre S: estado de reposo; estado libre A non-operating up state | uring non-required time . |
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|
5505 |
disabled state; outage F: etat´ d'incapicite´ S: estado de incapacidad |
||
|
34 |
Fascicle II.3 -- Suppl. No. 6 |
|
5506 |
A state of an item | haracterized by its inability to perform a required function , for any reason. external disabled state F: etat´ d'incapacite´ externe S: estado de incapacidad externa That subset of the disabled state | hen the item | s in an up state , but lacks required external resources. Fascicle II.3 -- Suppl. No. 6 35 |
5507 down state; internal disabled state
F: etat´ d'indisponibilite;´ etat´ d'incapacite´ interne
S: estado de indisponibilidad; estado de incapacidad interna
A state of an item | haracterized by a fault | r by a possible inability to perform a required function during preventive maintenance .
|
Note -- This state relates to availability performance . |
||
|
5508 |
up state F: etat´ de disponibilite´ S: estado de disponibilidad A state of an item | haracterized by the fact that it can perform a required function , assuming that the external |
resources, if required, are provided.
|
Note -- This state relates to availability performance . |
|||
|
5509 |
busy state F: etat´ occupe;´ occupation S: estado de ocupacion;´ estado de ocupado The state of an item | n which it performs a required function |
| or a user and for that reason is not accessible by other users.
5510 critical state
F: etat´ critique
S: estado critico´
A state of an item | ssessed likely to result in injury to persons or significant material damage.
Note -- A critical state | ay be the result of a critical fault , but not necessarily.
6001 maintenance philosophy
F: philosophie de maintenance
|
S: filosofia´ de mantenimiento A system of underlying principles for the organization and execution of the maintenance . |
|||
|
6002 |
maintenance policy F: politique de maintenance |
||
|
36 |
Fascicle II.3 -- Suppl. No. 6 |
S: politica´ de mantenimiento
A description of the interrelationship between the maintenance echelons , the indenture levels and the levels of maintenance to be applied for the maintenance of an item .
6003 maintenance
F: maintenance
S: mantenimiento
The combination of all technical and corresponding administrative actions, including supervision actions, intended to retain an item in, or restore it to, a state in which it can perform a required function .
Fascicle II.3 -- Suppl. No. 6 37
6004 preventive maintenance
F: maintenance preventive;´ entretien
S: mantenimiento preventivo
The maintenance | arried out at predetermined intervals or according to prescribed criteria and intended to reduce the probability of failure or the degradation of the functioning of an item .
6005 corrective maintenance; repair
F: maintenance corrective; reparation;´ depannage´
S: mantenimiento correctivo; reparacion´
The maintenance | arried out after fault recognition | nd intended to restore an item to a state in which it can perform a required function .
6006 deferred maintenance
F: maintenance differ´ ee´
S: mantenimiento diferido
Such corrective maintenance | hich is not immediately initiated after a fault recognition but is delayed in accordance with given maintenance rules.
6007 scheduled maintenance
F: maintenance programmee;´ entretien systematique´
|
S: mantenimiento programado The preventive maintenance | arried out in accordance with an established time schedule. |
|||
|
6008 |
unscheduled maintenance F: maintenance non programmee´ S: mantenimiento no programado The maintenance | arried out, not in accordance with an established time schedule, but, |
for example, after |
reception of an indication regarding the state of an item .
6009 on-site maintenance; in situ maintenance; field maintenance
F: maintenance in situ
S: mantenimiento local; mantenimiento sobre el terreno
Maintenance | erformed at the premises where the item | s used.
6010 off-site maintenance
38 Fascicle II.3 -- Suppl. No. 6
F: maintenance deport´ ee´
|
S: mantenimiento no local Maintenance | erformed at a place different from where the item is used. Note -- An example is the repair | f a sub-item at a maintenance centre. |
|||
|
6011 |
remote maintenance F: tel´ emaintenance´ S: mantenimiento remoto; telemantenimiento Maintenance | f an item | erformed without physical access of the personnel to the item . Fascicle II.3 -- Suppl. No. |
6 39 |
6012 automatic maintenance
F: maintenance automatique
|
S: mantenimiento automatico´ Maintenance | ccomplished without human intervention. |
|||
|
6013 |
function-affecting maintenance F: maintenance affectant les fonctions S: mantenimiento que afecta a la funcion´ A maintenance action | hat affects one or more of the required functions of a maintained item . Note -- Function-affecting maintenance | s divided into function-preventing maintenance |
and |
function-degrading maintenance .
6014 function-preventing maintenance
F: maintenance-arr| t; maintenance emp| chant l'accomplissement des fonctions
|
S: mantenimiento con discontinuidad de funciones A maintenance action | hat prevents a maintained item 6015 function-degrading maintenance |
F: maintenance avec degradation;´ maintenance degradant´ les fonctions
S: mantenimiento con degradacion´ de funciones
A maintenance action | hat affects one or more of the required functions | f a maintained item , but not to such extent as to cause complete loss of all the functions.
6016 function-permitting maintenance
F: maintenance en fonctionnement; maintenance en exploitation
|
S: mantenimiento sin discontinuidad de funciones A maintenance action | hat does not affect any of the required functions | f a maintained item . |
||
|
6017 |
level of maintenance F: niveau de maintenance S: nivel de mantenimiento The maintenance action | o be carried out at a specified indenture level . Note -- Examples of a maintenance action | re replacing a component, a printed circuit board, a subsystem, etc. |
|
|
40 |
Fascicle II.3 -- Suppl. No. 6 |
6018 maintenance echelon; line of maintenance
F: echelon´ de maintenance
S: escalon´ de mantenimiento; linea´ de mantenimiento
The position in an organization where specified levels of maintenance | re to be carried out on an item .
Note 1 -- Examples of maintenance echelons | re: field, repair shop, manufacturer.
Note 2 -- The maintenance echelon | s characterized by the skill of the personnel, the facilities available, the location, etc.
Fascicle II.3 -- Suppl. No. 6 41
6019 indenture level (for maintenance)
F: niveau d'intervention (pour la maintenance)
S: nivel de intervencion´ (para el mantenimiento)
A level of subdivision of an item | rom the point of view of a maintenance action .
Note 1 -- Examples of indenture levels | ould be a subsystem, a circuit board, a component.
Note 2 -- The indenture level | epends on the complexity of the item's construction, the accessibility to sub-items, skill level of maintenance personnel, test equipment facilities, safety considerations, etc.
6020 elementary maintenance activity
F: operation´ el´ ementaire´ de maintenance
|
S: accion´ elemental de mantenimiento The unit of work into which a maintenance activity may be broken down at a given indenture level . |
|||
|
6021 |
maintenance action; maintenance task F: operation´ de maintenance; t| che de maintenance S: accion´ de mantenimiento; tarea de mantenimiento A sequence of elementary maintenance activities | arried out for a given purpose. Note -- Examples are fault diagnosis , fault localization |
| nd function check-out or combinations thereof.
6022 supervision
F: surveillance; supervision
|
S: supervision´ Activity, performed either manually or automatically, intended to observe the state of an item . Note -- Automatic supervision | ay be performed internally or externally to the item . |
||
|
6023 |
controlled maintenance F: maintenance dirigee´ S: mantenimiento dirigido A method to sustain a desired quality of service | y the systematic application of analysis techniques using |
centralized supervisory facilities and/or sampling to minimize preventive maintenance and to reduce corrective maintenance .
6024 fault recognition
F: detection´ (de panne)
42 Fascicle II.3 -- Suppl. No. 6
|
S: deteccion´ (de una averia´ ) The event when a fault | s recognized. |
|||
|
6025 |
fault diagnosis F: diagnostic (de panne) S: diagnostico´ (de una averia)´ Actions taken for fault recognition , fault localization | nd cause identification. Fascicle II.3 |
-- Suppl. No. 6 43 |
6026 fault localization; fault location (deprecated in this sense)
F: localisation de panne
|
S: localizacion´ (de una averia)´ Actions taken to identify the faulty sub-item or sub-items at the appropriate indenture level . |
||
|
6027 |
fault correction F: correction (de panne) S: correccion´ (de una averia)´ Actions taken after fault localization | ntended to restore the ability of the faulty item to perform a required |
function .
6028 function check-out
F: verification´ (de fonctionnement)
|
S: verificacion´ de funcionamiento Actions taken after fault correction | o verify that the item 6029 restoration; recovery |
|
F: S: That |
retablissement´ restablecimiento; restauracion´ event when the item | egains the ability to perform a required function after a fault . |
||||
|
6030 |
maintenance entity |
||||
|
F: S: |
cellule de maintenance cellula de mantenimiento; entidad de mantenimiento |
A sub-item of a given item | efined with the intention that an alarm -- caused by a fault in that sub-item -- will be unambiguously referrable to the sub-item.
7 Time concepts (see also Figure 3)
7.1 Maintenance related times
7101 maintenance time
44 Fascicle II.3 -- Suppl. No. 6
F: temps de maintenance
S: tiempo de mantenimiento
The time interval | uring which a maintenance action | s performed on an item either manually or automatically, including technical delays and logistic delays .
Note -- Maintenance | ay be carried out while the item
| s performing a required function .
7102 maintenance man-hours (MMH)
F: duree´ equivalente´ de maintenance
S: duracion´ equivalente de mantenimiento; horas-hombre de mantenimiento
The accumulated durations of the maintenance times , expressed in hours, used by all maintenance personnel for a given type of maintenance action or over a given time interval .
Fascicle II.3 -- Suppl. No. 6 45
|
7103 |
active maintenance time |
Figure 3, p. 6 |
||||
|
F: S: |
temps de maintenance active tiempo de mantenimiento activo |
|
That part of the maintenance time | uring which a maintenance action Note -- Active maintenance may be carried out while the item 7104 preventive maintenance time F: temps de maintenance preventive´ S: tiempo de mantenimiento preventivo |
| s performed on an item , either |
That part of the maintenance time | uring which preventive maintenance | s performed on an item , including technical delays and logistic delays inherent in preventive maintenance .
46 Fascicle II.3 -- Suppl. No. 6
7105 repair time; corrective maintenance time
F: temps de reparation;´ temps de maintenance corrective
S: tiempo de reparacion;´ tiempo de mantenimiento correctivo
That part of the maintenance time | uring which corrective maintenance | s performed on an item , including technical delays and logistic delays inherent in corrective maintenance .
|
7106 |
active preventive maintenance time |
|||
|
F: S: That |
temps de maintenance preventive´ active tiempo de mantenimiento preventivo activo part of the active maintenance time | uring which actions of preventive maintenance are performed on an |
item .
|
7107 |
active repair time; active corrective maintenance time F: temps de reparation´ active; temps de maintenance corrective active S: tiempo de reparacion´ activo; tiempo de mantenimiento correctivo activo That part of the active maintenance time | uring which actions of corrective maintenance are performed on an |
item .
7108 undetected fault time
F: temps de non-detection´ de panne
|
S: tiempo de no deteccion´ de una averia´ The time interval | etween a failure | nd recognition of the resulting fault . |
||
|
7109 |
administrative delay (for corrective maintenance) F: delai´ administratif (pour la maintenance corrective) S: retardo administrativo (para el mantenimiento correctivo); demora administrativa The accumulated time | uring which an action of corrective maintenance | n a faulty item is not performed due to |
administrative reasons.
|
7110 |
logistic delay |
||||
|
F: S: That |
delai´ logistique retardo logistico;´ demora logistica´ accumulated time | uring which a maintenance action |
| annot be performed due to the necessity to acquire maintenance resources, excluding any administrative delay .
Note -- Logistic delays | an be due to, e.g. travelling to unattended installations, awaiting the arrival of spare parts, specialists or test equipment.
Fascicle II.3 -- Suppl. No. 6 47
|
7111 |
F: S: That |
fault correction time temps de correction de panne tiempo de correccion´ de una averia´ part of active repair time | uring which fault correction |
| s performed.
7112 technical delay
F: delai´ technique
S: retardo tecnico;´ demora tecnica´
The accumulated time | ecessary to perform auxiliary technical actions associated with the maintenance action itself.
48 Fascicle II.3 -- Suppl. No. 6
7113 check-out time
F: temps de verification´ (du fonctionnement)
|
S: That |
tiempo de verificacion´ (de funcionamiento) part of active repair time | uring which function check-out | s performed. |
||||
|
7114 |
fault localization time; fault location time (deprecated) |
||||
|
F: S: That |
temps de localisation (de panne) tiempo de localizacion´ de una averia´ part of active repair time | uring which fault localization | s performed. |
|
7.2 7201 |
Item-state related times operating time |
||||
|
F: S: |
temps de fonctionnement tiempo de funcionamiento |
|
The time interval | uring which an item | s an operating state . |
|||
|
7202 |
non-operating time F: temps de non-fonctionnement S: tiempo de no funcionamiento The time interval | uring which an item | s in a non-operating state . |
||
|
7203 |
required time F: periode´ requise S: periodo requerido The time interval | uring which the user requires the item |
| o be in a condition to perform a required function .
7204 non-required time
F: periode´ non requise
S: periodo no requerido
The time interval | uring which the user does not require the item | o be in a condition to perform a required function .
Fascicle II.3 -- Suppl. No. 6 49
7205 stand-by time
F: periode´ d'attente
S: tiempo de espera (en reserva)
|
The time interval | uring which an item | s in a stand-by state . |
||
|
7206 |
idle time; free time F: periode´ vacante; temps mort; temps libre S: tiempo de reposo; tiempo muerto; tiempo libre The time interval | uring which an item | s in a free state . |
|
|
50 |
Fascicle II.3 -- Suppl. No. 6 |
7207 disabled time
F: temps d'incapacite´
|
S: tiempo de incapacidad The time interval | uring which an item | s in a disabled state . |
|||
|
7208 |
down time F: temps d'indisponibilite´ S: tiempo de indisponibilidad The time interval | uring which an item | s in a down state . |
||
|
7209 |
accumulated down time F: duree´ cumulee´ d'indisponibilite´ S: tiempo de indisponibilidad acumulado The sum of the duration of down times | ver a given time interval . |
||
|
7210 |
external disabled time; external loss time F: temps d'incapacite´ externe S: tiempo de incapacidad externa The time interval | uring which an item | s in an external disabled state . |
||
|
7211 |
up time F: temps de disponibilite;´ temps de bon fonctionnement S: tiempo de disponibilidad The time interval | uring which an item | s in an up state . |
||
|
7.3 7301 |
Time concepts related to reliability performance time to first failure |
|
S: tiempo hasta el primer fallo Total time duration | f the operating time | f an item 7302 time to failure |
Fascicle II.3 -- Suppl. No. 6 51
F: duree´ de fonctionnement avant defaillance´
S: tiempo hasta el fallo
Total time duration | f the operating time | f an item , from the instant of time it goes from a down state to an up state , after a corrective maintenance action , until the next failure .
7303 time between failures
F: temps entre defaillances´
|
52 |
S: tiempo entre fallos The time duration | etween two successive failures | f a repaired item . Note 1 -- Those parts of non-operating time | hich are included must be identified. Note 2 -- In some applications only the up time | s considered. Fascicle II.3 -- Suppl. No. 6 |
7304 time to restoration; time to recovery
F: temps de panne
|
S: tiempo de averia´ The time interval | uring which an item | s in a down state | ue to a failure . |
||
|
7305 |
useful life F: (duree´ de) vie utile S: vida util´ Under given conditions, the time interval | eginning at a given instant of time , and ending when the failure |
intensity becomes unacceptable or when the item is considered unrepairable as a result of a fault .
7306 early failure period
F: periode´ initiale de defaillance´
S: periodo de fallos inicial
That possible early period in the life of an item , beginning at a given instant of time and during which the instantaneous failure intensity for a repaired item or the instantaneous failure rate for a non-repaired item decreases rapidly.
|
Note -- In any particular case, it is necessary to explain what is meant by ``decreases rapidly''. |
|||
|
7307 |
constant failure intensity period F: periode´ d'intensite´ constante de defaillance´ S: periodo de intensidad de fallos constante That possible period in the life of a repaired item | uring which the failure intensity is approximately constant. Note -- In any particular case it is necessary to explain what is meant by ``approximately constant''. |
||
|
7308 |
constant failure rate period F: periode´ de densite´ constante de defaillance;´ periode´ de taux constant de defaillance´ S: periodo de tasa de fallos constante That possible period in the life of a non-repaired item | uring which the failure rate is approximately constant. Note -- In any particular case it is necessary to explain what is meant by ``approximately constant''. |
||
|
7309 |
wear-out failure period F: periode´ de defaillance´ par vieillissement; periode´ de defaillance´ par usure S: periodo de fallos por envejecimiento That possible later period in the life of an item |
| uring which the instantaneous failure intensity for a repaired item or the instantaneous failure rate for a
Fascicle II.3 -- Suppl. No. 6 53
non-repaired item increases rapidly.
Note -- In any particular case it is necessary to explain what is meant by ``increases rapidly''. 54 Fascicle II.3 -- Suppl. No. 6
|
8.1 8101 |
Availability performance instantaneous availability; pointwise availability; A(t) (symbol) |
||||
|
F: S: |
disponibilite´ (instantanee),´ A(t) | symbole) disponibilidad instantanea,´ A(t) | simbolo)´ |
The probability | hat an item | s in an up state | t a given instant of time , t .
|
Note -- In French the term disponibilite´ | s also used to denote the performance quantified by this probability . |
||
|
8102 |
instantaneous unavailability; pointwise unavailability; U(t) (symbol) F: indisponibilite´ (instantanee),´ U(t) | symbole) S: indisponibilidad instantanea,´ U(t) | simbolo)´ The probability that an item | s in a down state | t a given instant of time , t . |
|
|
8103 |
mean availability, A (t¯1, | ¯2) (symbol) F: disponibilite´ moyenne, A | (t |
|
|
1, t2) (symbole) |
||
|
S: disponibilidad media, A | (t |
||
|
1, t2) (simbolo)´ |
||
|
The normalized integral of the instantaneous availability | n a given time interval (t |
||
|
1, t2). |
||
|
Note -- The mean availability | s related to the instantaneous availability as A | fR (t |
||
|
2) = |
||
|
[Formula Deleted] |
||
|
2 above int above t~1 } @ |
||
|
A (t ) dt . |
||
|
8104 |
mean unavailability, U (t¯1, t¯2) (symbol) F: indisponibilite´ moyenne, U | (t |
|
|
1, | fIt2) (symbole) |
||
|
S: indisponibilidad media, U | (t |
||
|
1, | fIt2) (simbolo)´ |
||
|
The normalized integral of the instantaneous unavailability | n a stated time interval (t |
||
|
1, | fIt2). |
||
|
Note -- The mean unavailability | s related to the instantaneous unavailability as U | fR (t |
||
|
2) = |
||
|
[Formula Deleted] |
||
|
2 above int above t~1 } @ |
||
|
Fascicle II.3 -- Suppl. No. 6 55 |
U (t ) dt .
8105 (asymptotic) availability; (steady-state) availability; A (symbol)
F: disponibilite´ asymptotique; disponibilite,´ A
| symbole)
S: disponibilidad (asintotica);´ disponibilidad (en regimen´ permanente); A | simbolo)´
The limit, if this exists, of the instantaneous availability
| hen the time tends to infinity.
|
Note |
-- Under certain conditions, for instance constant failure rate and constant repair rate, the asymptotic A = |
|
|
where |
MDT | s the mean down time
MUT | s the mean up time .
56 Fascicle II.3 -- Suppl. No. 6
8106 asymptotic unavailability, U (symbol)
F: indisponibilite´ asymptotique, U | symbole)
S: indisponibilidad asintotica,´ U | simbolo)´
The limit, if this exists, of the instantaneous unavailability | hen the time tends to infinity.
Note -- Under certain conditions, for instance constant failure rate and constant repair rate, the asymptotic unavailability may be expressed as:
U =
@ { fIMDT } over { fIMDT~+~MUT } @
|
where MDT | s the mean down time MUT | s the mean up time . 8107 asymptotic mean availability, |
A (symbol) |
F: disponibilite´ moyenne asymptotique, A | (symbole)
|
S: disponibilidad media asintotica,´ A | (simbolo)´ The limit, if this exists, of the mean availability | ver a time interval (t |
|
|
1, | fIt2) when t2tends to infinity. |
|
|
Note 1 -- The asymptotic mean availability | s related to the mean availability as A | fR = lim A | fR (t |
|
|
1, t 2) |
|
|
A | fR = t |
|
|
2 ñ¥ |
|
Note 2 -- When such a limit exists it is not dependent on t |
|||
|
1. |
|||
|
8108 |
asymptotic mean unavailability, U (symbol) F: indisponibilite´ moyenne asymptotique, U | (symbole) S: indisponibilidad media asintotica´ , U | (simbolo)´ The limit, if this exists, of the mean unavailability | ver a time interval | t |
||
|
1, | fIt2) when t2tends to infinity. |
|||
|
Note 1 -- The asymptotic mean unavailability | s related to the mean unavailability | s |
U | fR = lim U | fR (t 1, t 2)
U | fR = t 2 ñ¥
Note 2 -- When such a limit exists it is not dependent on t1.
8109 mean up time (MUT)
Fascicle II.3 -- Suppl. No. 6 57
F: temps moyen de disponibilite;´ duree´ moyenne de disponibilite´ (TMD)
S: tiempo medio de disponibilidad (TMD)
|
The expectation | f the up time . |
|||
|
8110 |
mean accumulated down time (MADT) F: duree´ cumulee´ moyenne d'indisponibilite´ S: tiempo medio acumulado de indisponibilidad |
(TMAI) |
|
|
The expectation | f the accumulated down time . |
|||
|
58 |
Fascicle II.3 -- Suppl. No. 6 |
8111 instantaneous availability of a leased circuit
F: disponibilite´ instantanee´ d'un circuit loue´
S: disponibilidad instantanea´ de un circuito arrendado
The probability | hat, under stated operating conditions, a leased circuit can perform a required function when requested by the subscriber.
|
8.2 8201 |
Reliability performance reliability, R (symbol) |
||||
|
F: S: |
fiabilite,´ R | symbole) fiabilidad, R | simbolo)´ |
The probability | hat an item | an perform a required function | nder stated conditions for a given time interval .
Note 1 -- It is generally assumed that the item | s in a state to perform this required function at the beginning of the time interval .
|
Note 2 -- In French, the term fiabilite´ | s also used to denote the performance quantified by this probability . |
||
|
8202 |
(instantaneous) failure rate, l(t) (symbol) F: densite´ (temporelle) (instantanee)´ de defaillance;´ taux (instantane)´ de defaillance,´ l(t) | (symbole) S: tasa (instantanea)´ de fallos, l(t) | simbolo)´ The limit, if this exists, of the ratio of the conditional probability | hat the time to failure , T , of an item falls within |
a given time interval , (t , | fIt +?63t ), to the length of this interval, ?63t , when ?63t tends to zero, given that the item is in a state to perform a required function at the beginning of the time interval .
Note -- The instantaneous failure rate | s expressed by formula as:
l (t ) = lim l (t ) = ?63 (t ) ñ0+ @ { fIPr (t~<~T~@t~+~?63~t | T~>~t ) } over { 63t } @
where T | s the instant of time | f failure .
|
The formula is also applicable if T | enotes the time to failure . |
|||
|
8203 |
mean failure rate, l (t¯1, | ¯2) (symbol) F: taux moyen de defaillance;´ densite´ (temporelle) moyenne de defaillance,´ l | (t |
||
|
1, | fIt2) (symbole) |
|||
|
S: tasa media de fallos, l | (t |
|||
|
1, | fIt2) (simbolo)´ |
|||
|
The normalized integral of the instantaneous failure rate | ver a given time interval , (t |
|||
|
1, | fIt2). |
|||
|
Note -- The mean failure rate | elates to instantaneous failure rate as l Fascicle II.3 -- Suppl. No. 6 |
59 |
(t
|
, t 1 |
1) = |
@ pile { fIt~2 above int above t~1 } @ l (t ) dt .
8204 (instantaneous) failure intensity, z(t) (symbol)
|
F: intensite´ (instantanee)´ |
de defaillance,´ |
z(t) |
S: intensitad (instantanea)´ de fallos, z(t) | (simbolo)´
The limit, if this exists, of the ratio of the mean number of failures | f a repaired item in a time interval , (t , | fIt | | 63t ), to the length of this interval, ?63t , when the length of the time interval tends to zero.
60 Fascicle II.3 -- Suppl. No. 6
Note -- The instantaneous failure intensity | s expressed by formula as:
z (t ) = lim z (t ) = ?63t ñ0+ @ { fIE~[N (t~+~?63t ) --~N (t )] } over { 63t } @
where N | t ) is the number of failures | n the time interval | (0, | fIt ).
8205 mean failure intensity, z (t¯1, | ¯2) (symbol)
F: intensite´ moyenne de defaillance,´ z | (t1, | fIt2) (symbole)
|
S: intensidad media de fallos, z | (t |
|
|
1, | fIt2) (simbolo)´ |
|
|
The normalized integral of the instantaneous failure intensity | over a given time interval | (t |
|
|
1, | fIt2). |
|
|
Note -- The mean failure intensity | s related to instantaneous failure intensity as: z | fR (t |
|
|
2) = |
|
|
[Formula Deleted] |
|
|
2 above int above t~1 } @ z (t ) dt . |
|
8206 |
mean time to first failure (MTTFF) F: duree´ moyenne de fonctionnement avant la premiere defaillance´ |
(MTTFF) |
|
S: tiempo medio hasta el primer fallo (MTTFF) The expectation | f the time to first failure . |
|||
|
8207 |
mean time to failure (MTTF) F: duree´ moyenne de fonctionnement avant defaillance´ |
(MTTF) |
|
|
S: tiempo medio hasta el fallo (MTTF) The expectation | f the time to failure . |
|||
|
8208 |
mean time between failures (MTBF) F: moyenne des temps entre defaillances´ (MTBF) S: tiempo medio entre fallos (MTBF) The expectation | f the time between failures . |
||
|
8209 |
failure rate acceleration factor F: facteur d'accel´ eration´ de la densite´ de defaillance;´ |
facteur d'accel´ eration´ du taux de defaillance´ |
|
|
S: factor de aceleracion´ de la tasa de fallos |
|||
|
Fascicle II.3 -- Suppl. No. 6 61 |
|
The ratio of the accelerated testing failure rate | o the failure rate under stated reference test conditions. Note -- Both failure rates | efer to the same time period in the life of the tested items . |
||
|
8210 |
failure intensity acceleration factor F: facteur d'accel´ eration´ de l'intensite´ de defaillance´ S: factor de aceleracion´ de la intensidad de fallos In a time interval | f given duration , whose beginning is specified by a fixed age of a repaired item , the ratio of |
the number of failures obtained under two different sets of stress conditions.
62 Fascicle II.3 -- Suppl. No. 6
|
8.3 8301 |
Maintainability performance maintainability |
||||
|
F: S: |
maintenabilite´ mantenibilidad |
The probability | hat a given active maintenance action , for an item | nder given conditions of use can be carried out within a stated time interval , when the maintenance is performed under stated conditions and using stated procedures and resources.
Note -- In French the term maintenabilite´ | s also to denote the performance quantified by this probability .
8302 (instantaneous) repair rate, m(t) (symbol)
F: densite´ (temporelle) (instantanee),´ de reparation,´ m (t) | symbole)
S: tasa (instantanea)´ de reparaciones, m(t) | simbolo)´
The limit, if this exists, of the ratio of the conditional probability | hat the corrective maintenance action terminates in a time interval , (t , t +?63t ) to the length of this time interval , when ?63t tends to zero, given that the action had not terminated at the beginning of the time interval .
Note -- The instantaneous repair rate | s expressed by formula as:
m (t ) = lim m (t ) = ?63 (t ) ñ0 @ { fIPr (t~<~T~@t~+~?63~t | T~>~t ) } over { 63t } @
where T | is the instant of time | f restoration .
|
T | ay also represent the time to restoration . |
|||
|
8303 |
mean repair rate, m (t¯1, | ¯2) (symbol) F: densite´ (temporelle) moyenne de reparation,´ m | fR (t |
||
|
1, | fIt2) (symbole) |
|||
|
S: tasa media de reparaciones, m | fR (t |
|||
|
1, | fIt2) (simbolo)´ |
|||
|
The normalized integral of the instantaneous repair rate | ver a given time interval (t |
|||
|
1, | fIt2). |
|||
|
Note -- The mean repair rate | s related to instantaneous repair rate as: m |
|||
|
2) = |
|||
|
[Formula Deleted] |
|||
|
2 above int above t~1 } @ m |
|||
|
(t ) dt . |
|||
|
8304 |
mean maintenance man-hours Fascicle II.3 -- Suppl. No. 6 |
63 |
F: duree´ moyenne equivalente´ de maintenance
S: duracion´ media equivalente de mantenimiento; media de horas-hombre de mantenimiento
The expectation | f the maintenance man-hours .
8305 mean down time (MDT)
|
F: temps moyen d'indisponibilite;´ duree´ moyenne d'indisponibilite´ (TMI) S: tiempo medio de indisponibilidad (TMI) The expectation | f the down time . |
|||
|
8306 |
mean repair time (MRT) F: duree´ moyenne de reparation´ S: tiempo medio de reparacion´ The expectation | f the repair time . |
||
|
64 |
Fascicle II.3 -- Suppl. No. 6 |
8307 p-fractile repair time
F: quantile-p de la duree´ de reparation´
|
S: cuantil-p del tiempo de reparacion´ The p-fractile | alue of the repair time . |
||
|
8308 |
mean active repair time (MART) F: duree´ moyenne de reparation´ active S: tiempo medio de reparacion´ activa The expectation | f the active repair time . |
|
|
8309 |
p-fractile active repair time F: quantile-p de la duree´ de reparation´ active S: cuantil-p del tiempo de reparacion´ activa The p-fractile | alue of the active repair time . |
|
|
8310 |
mean time to restoration (MTTR); mean time to recovery; mean time to repair (deprecated) F: duree´ moyenne de panne; moyenne des temps pour la t| che de reparation´ (MTTR) S: tiempo medio hasta el restablecimiento (MTTR) The expectation | f the time to restoration . |
|
|
8311 |
fault coverage F: couverture de pannes S: cobertura de averias´ The proportion of faults | f an item | hat can be recognized under given conditions. |
|
|
8312 |
repair coverage F: couverture des reparations´ S: cobertura de reparaciones The proportion of faults | f an item | hat can be successfully removed. |
|
|
8.4 8401 |
Maintenance support performance mean administrative delay (MAD) Fascicle II.3 -- Suppl. No. 6 65 |
F: duree´ moyenne du delai´ administratif
|
S: retardo medio administrativo; demora media administrativa The expectation | f the administrative delay . |
||
|
8402 |
p-fractile administrative delay F: quantile-p du delai´ administratif S: cuantil-p del retardo administrativo; cuantil-p de la demora administrativa The p-fractile | alue of the administrative delay . |
|
|
8403 |
mean logistic delay (MLD) F: duree´ moyenne du delai´ logistique S: retardo medio logistico;´ demora media logistica´ The expectation | f the logistic delay . |
|
|
66 |
Fascicle II.3 -- Suppl. No. 6 |
8404 p-fractile logistic delay
F: quantile-p du delai´ logistique
S: cuantil-p del retardo logistico;´ cuantil-p de la demora logistica´
The p-fractile | alue of the logistic delay .
|
9.1 9101 |
Test concepts test |
||||
|
F: S: An |
essai prueba experiment made in order to measure or classify a characteristic . |
||||
|
9102 |
compliance test |
||||
|
F: S: |
essai de conformite´ prueba de conformidad |
|
A test | sed to show whether or not a characteristic | f an item | omplies with the stated requirements. |
||
|
9103 |
determination test F: essai de determination´ S: prueba de determinacion´ A test | sed to establish the value of a characteristic . |
|
|
9104 |
laboratory test F: essai en laboratoire S: prueba de laboratorio A compliance test | r a determination test | ade under prescribed and controlled conditions which may or may |
not simulate field conditions.
9105 field test
F: essai dans des conditions d'exploitation
S: prueba en condiciones de explotacion;´ prueba en condiciones reales
Fascicle II.3 -- Suppl. No. 6 67
A compliance test | r determination test | ade in the field where operating, environmental, maintenance and measurement conditions are recorded.
9106 endurance test
F: essai d'endurance
S: prueba de resistencia
A test | arried out over a time interval | o investigate how the properties of an item are affected by the application of stated stresses and by their time duration .
9107 accelerated test
F: essai accel´ er´ e´
S: prueba acelerada
A test | n which the applied stress level is chosen to exceed that stated in the reference conditions in order to shorten the time duration required to observe the stress response of the item , or to magnify the responses in a given time duration .
Note -- To be valid, an accelerated test | hall not alter the basic fault modes and failure mechanisms , or their relative prevalence.
68 Fascicle II.3 -- Suppl. No. 6
9108 step stress test
F: essai sous contrainte echelonn´ ee´
S: prueba de esfuerzo escalonado
A test | onsisting of several stress levels applied sequentially for periods of equal time duration | o an item , in such a way that during each time interval a stated stress level is applied and the stress level is increased from one time interval to the next.
9109 screening test
F: essai de selection´
S: prueba de seleccion´
A test , or combination of tests , intended to remove or detect unsatisfactory items | r those likely to exhibit early failures .
9110 time acceleration factor
F: facteur d'accel´ eration´ temporelle
S: factor de aceleracion´ temporal
The ratio between the time durations | ecessary to obtain the same stated number of failures | r degradations in two equal size samples under two different sets of stress conditions involving the same failure mechanisms and fault modes and their relative prevalence.
|
Note -- One of the two sets of stress conditions should be a reference set. |
||
|
9111 |
maintainability verification F: verification´ de la maintenabilite´ S: verificacion´ de la mantenibilidad A procedure applied for the purpose of determining whether the requirements for maintainability performance |
measures for an item has been achieved or not.
|
Note -- The procedures may range from analysis of appropriate data to a maintainability demonstration . |
|||
|
9112 |
maintainability demonstration F: verification´ experimentale´ de maintenabilite´ S: demostracion´ de la mantenibilidad A maintainability verification | erformed as a compliance test . |
||
|
9.2 |
Data concepts Fascicle II.3 -- Suppl. No. 6 69 |
9201 observed data
F: valeur observee;´ donnee´ observee´
S: datos observados; valores observados
Values related to an item | r a process obtained by direct observation.
|
Note -- Values referred to could be events, time instants, time intervals , etc. |
||
|
9202 |
test data F: donnees´ d'essai S: datos de prueba Observed data | btained during tests . |
|
|
70 |
Fascicle II.3 -- Suppl. No. 6 |
9203 field data
F: donnee´ d'exploitation
|
S: datos de explotacion´ Observed data | btained during field operation. |
|||
|
9204 |
reference data F: valeur de ref´ erence;´ donnees´ de ref´ erence´ S: datos de referencia; valores de referencia Data, which by general agreement may be used for prediction |
| nd/or comparison with observed data .
|
9.3 9301 |
Design concepts redundancy |
||||
|
F: S: |
redondance redundancia |
|
In an item , the existence of more than one means for performing a required function . |
|||
|
9302 |
active redundancy F: redondance active S: redundancia activa That redundancy | herein all means for performing a required function | re intended to operate simultaneously. |
||
|
9303 |
standby redundancy F: redondance en attente; redondance passive; redondance en secours S: redundancia pasiva; redundancia de reserva That redundancy | herein one means for performing a required function | s intended to operate, while the |
alternative means are inoperative until needed.
|
9304 |
fail safe F: proteg´ e´ contre defaillances´ (critique); a s| rete´ integr´ ee |
ee´ |
S: prevencion´ de fallos
A designed property of an item | hich prevents its failures
| rom resulting in critical faults .
Fascicle II.3 -- Suppl. No. 6 71
9305 fault tolerance
F: tolerance´ aux pannes
S: tolerancia a las averias´
The attribute of an item | hat makes it able to perform a required function | n the presence of certain given sub-item faults .
9306 fault masking
F: masquage de panne
S: enmascaramiento de averia´
The condition in which a fault | xists in a sub-item of an item | ut cannot be recognized because of a feature of the item or because of another fault of the sub-item or of another sub-item.
72 Fascicle II.3 -- Suppl. No. 6
|
9.4 9401 |
Analysis concepts prediction |
||||
|
F: S: 1) |
prevision;´ prediction´ prevision;´ prediccion´ The process of computation used to obtain (a) predicted |
| alue(s) of a quantity.
2) The predicted | alue(s) of a quantity.
9402 reliability model
|
S: modelo de fiabilidad A mathematical model used for prediction | r estimation | f reliability measures |
| f an item or for similar |
|
|
purposes. 9403 fault modes and effects analysis (FMEA) F: analyse des modes de panne et de leurs effets (AMDE) S: analisis´ de los modos de averia´ y de sus efectos (AMAE) |
A qualitative method of reliability | nalysis which involves the study of the fault modes | hich can exist in every sub-item of the item and the determination of the effects of each fault mode on other sub-items of the item and on the required functions of the item .
|
9404 |
fault modes, effects and criticality analysis (FMECA) F: analyse des modes de panne, de leurs effets et de leur criticite´ (AMDEC) S: analisis´ de los modos de averia,´ sus efectos y su criticidad (AMAEC) Fault modes and effect analysis | ogether with a consideration of the probability | f occurrence and a ranking of |
the seriousness of the fault .
9405 fault tree analysis (FTA)
F: analyse par arbre de panne
S: analisis´ en arbol´ de averias´
An analysis to determine which fault modes | f the sub-items or external events, or combinations thereof, may result in a stated fault mode of the item , resulting in a fault tree .
9406 stress analysis
Fascicle II.3 -- Suppl. No. 6 73
F: analyse de contraintes
S: analisis´ de esfuerzos
A quantitative or qualitative determination of the physical, chemical or other stresses an item | s subjected to under given use conditions.
9407 reliability block diagram
F: diagramme de fiabilite´
S: diagrama de bloques de fiabilidad
Block diagram showing, for one or more functional modes | f a complex item , how faults | f the sub-items represented by the blocks, or combinations thereof, result in a fault of the item .
74 Fascicle II.3 -- Suppl. No. 6
9408 fault tree
F: arbre de panne
S: arbol´ de averias´
A logic diagram showing which fault modes | f sub-items or external events, or combinations thereof, result in a given fault mode of the item .
9409 state-transition diagram
F: diagramme de transition
|
S: diagrama de transicion´ A diagram showing the set 9410 stress model |
de estados of possible states of an item | nd the possible one step transitions between these |
S: modelo de esfuerzos
A mathematical model which describes how a reliability performance measure | f an item | aries as a function of the applied stresses.
9411 fault analysis
F: analyse des pannes
S: analisis´ de averias´
The logical, systematic examination of an item | r its diagram(s) to identify and analyse the probability , causes and consequences of potential and real faults .
9412 maintainability model
S: modelo de mantenibilidad
A mathematical model used for prediction | r estimation | f maintainability performance measures of an item or for similar purposes.
|
Note -- An example is the maintenance tree . |
||
|
9413 |
maintainability prediction F: prevision´ de maintenabilite;´ prediction´ de maintenabilite´ S: prevision´ de la mantenibilidad; prediccion´ de la mantenibilidad An activity performed with the intention to forecast the numerical values of a maintainability performance |
measure of an item , taking into account the maintainability performance and reliability performance measures of its
Fascicle II.3 -- Suppl. No. 6 75
sub-items, under given operational and maintenance conditions.
9414 maintenance tree
F: arbre de maintenance
|
S: arbol´ de mantenimiento A logic diagram showing the pertinent alternative sequences of elementary maintenance activities |
| o be |
|
|
performed on an item and the conditions for their choice. 9415 maintainability allocation; maintainability apportionment F: repartition´ de la maintenabilite´ S: distribucion´ de la mantenibilidad; asignacion´ de la mantenibilidad |
A procedure applied during the design of an item | ntended to apportion the requirements for maintainability performance measures for an item to its sub-items according to given criteria.
76 Fascicle II.3 -- Suppl. No. 6
|
9.5 9501 |
Improvement processes learning process |
||||
|
F: S: |
apprentissage aprendizaje |
Growth in experience and familiarity by personnel with design or constructional techniques, which reduces the risk of future mistakes .
9502 burn-in
F: rodage
S: rodaje
A process of reliability improvement | f hardware, employing operation of every item | n a prescribed environment, with successive fault correction , replacement or removal at every failure , during the steeply falling failure intensity period within the early failure period .
9503 reliability growth
F: croissance de la fiabilite´
S: crecimiento de la fiabilidad; incremento de la fiabilidad
A condition characterized by a progressive improvement of a reliability performance measure | f an item , or population of similar items , with time.
|
Note -- A growth can result either from active improvement or from burn-in . |
|||
|
9504 |
reliability improvement F: amelioration´ de fiabilite´ S: mejora de la fiabilidad A process undertaken with the deliberate intention of promoting reliability growth |
| y the elimination of |
systematic faults .
9505 maintainability programme
F: programme de maintenabilite´
S: programa de mantenibilidad
A detailed plan, including the human and material resources, procedures, tasks and responsibilities during the life of an item , intended to determine the fulfilment of the requirements for maintainability performance measures for an item and facilitate the planning of the maintenance .
Fascicle II.3 -- Suppl. No. 6 77
1001 true | ..
F: ... | rai
S: ... | erdadero
The ideal value which characterizes a quantity perfectly defined under the conditions which exist at the moment when that quantity is observed, or the subject of a determination.
Note -- This value could be arrived at only if all causes of measurement error were eliminated.
78 Fascicle II.3 -- Suppl. No. 6
1002 predicted | ..
F: ... | redit;´ ... | revu´
S: ... | revisto; ... | redicho
The numerical value assigned to a quantity, before the quantity is actually observable, computed on the basis of earlier observed or estimated values of the same quantity or of other quantities using a mathematical model.
1003 extrapolated | ..
F: ... | xtrapole´
S: ... | xtrapolado
The predicted | alue based on estimated | alues for one or a set of conditions, intended to apply to other conditions such as time, maintenance and environmental conditions.
1004 estimated | ..
F: ... | stime´
S: ... | stimado
The value obtained as the result of an estimation .
Note -- The result may be expressed either as a single numerical value, a point estimate, or as a confidence interval .
1005 intrinsic | ..; inherent | ..
|
S: ... | ntrinseco;´ ... | nherente Value of a measure | etermined when maintenance and operational conditions are assumed to be ideal. |
|||
|
1006 |
operational | .. F: ... | perationnel´ S: ... | peracional Value determined under given operational conditions. |
||
|
1007 |
mean | ..; average | .. (deprecated) F: ... | oyen (adjectif) S: ... | edio (adjetivo); promedio | desaconsejado) 1) The value obtained as the expectation | f a random variable . 2) The normalized integral of a time dependant quantity. Fascicle II.3 -- Suppl. No. 6 79 |
1008 p-fractile | ..
F: ... | uantile-p
S: cuantil-p de | ..
|
The value obtained as the p-fractile | f the distribution of a random variable . |
||
|
1009 |
instantaneous | .. F: ... | nstantane´ S: ... | nstantaneo´ The value of a measure | etermined for a given instant of time . |
|
|
80 |
Fascicle II.3 -- Suppl. No. 6 |
PART II
Statistical vocabulary
The quantitative applications of measures for quality of service, network performance, dependability and trafficability performance requires a fundamental set of statistical concepts.
This Part provides the terms and definitions for such applications.
2001 characteristic
|
S: caracteristica´ A property which helps to differentiate between the individuals of a given population. Note -- The differentiation may be either quantitative (by variables) or qualitative (by attributes). |
||
|
2002 |
probability F: probabilite´ S: probabilidad For practical reasons, it may be considered that, whenever the conditions of a test | an be reproduced, the |
probability Pr (E) | of an event E | ccurring is the value around which the occurrence frequency of the latter oscillates and towards which it tends when the number of tests are indefinitely increased.
Note -- The concept of probability | ay be introduced in either of two forms, depending on whether it is intended to designate a degree of belief or whether it is considered as the limit value of a frequency. In both cases, its introduction requires that some precautions be taken which cannot be developed within the context of an International Standard and for which users should refer to specialized literature.
2003 random variable; variate
F: variable aleatoire´
S: variable aleatoria
A variable which may take any of the values of a specified set of values and with which is associated a probability distribution.
Note -- A random variable | hich may take only isolated values is said to be ``discrete''. A random variable | hich may take all the values of a finite or infinite interval is said to be ``continuous''.
2004 random process
F: processus aleatoire;´ processus stochastique
Fascicle II.3 -- Suppl. No. 6 81
S: proceso aleatorio; proceso estocastico´
A collection of time-dependent random variables | here the values are governed by a given set of multivariate distributions for all combinations of the random variables .
2005 distribution function
F: fonction de repartition´
S: funcion´ de distribucion´
A function giving, for every value x , the probability | hat the random variable X | s less than or equal to x :
F (x ) = Pr (X x ).
82 Fascicle II.3 -- Suppl. No. 6
2006 probability density function
F: densite´ de probabilite´
|
S: funcion´ densidad de probabilidad The derivative, if this exists, of the distribution function : f (x ) = |
||
|
2007 |
p-fractile; p-quantile (of a probability distribution) F: quantile d'ordre p; quantile-p (d'une loi de probabilite)´ S: cuantil-p; cuantil de orden p (de una ley de distribucion´ de probabilidades) If p | s a number between 0 and 1, the p-fractile | s the value of the random variable | or which the distribution |
function equals p or ``jumps'' from a value less than or equal to p to a value greater than p .
Note -- It is possible that the distribution function
| quals p throughout the interval between consecutive possible values of the variate. In this case, any value in this interval may be considered as the p-fractile .
|
2008 |
expectation (of a random variable); mean (of a random variable) |
||||
|
F: S: a) |
esperance´ mathematique´ (d'une variable aleatoire);´ moyenne (d'une variable aleatoire)´ esperanza matematica´ (de una variable aleatoria); media (de una variable aleatoria) For a discrete random variable X | aking the values x |
||||
|
iwith the probabilites pi, |
|||||
|
E (X ) = s" p i x |
|||||
|
i |
the sum being extended over all the values xiwhich can be taken by X .
b) For a continuous random variable X | aving the probability density function f (x ),
E (X ) =
@ int @ x f (x ) dx
the integral being extended over all values of the interval of variation of X .
Note 1 -- No distinction is made between the expectation
| f a random variable | nd that of a probability distribution.
Note 2 -- The term mean | s also used with other meanings, for example as the normalized integral over a time interval .
2009 variance (of a random variable)
Fascicle II.3 -- Suppl. No. 6 83
F: variance (d'une variable aleatoire)´
S: varianza (de una variable aleatoria)
|
The expectation | f the square of the difference between a random variable | nd the expectation of this variable. |
||
|
2010 |
standard deviation, d (symbol) F: ecart-type,´ d (symbole) S: desviacion´ tipica,´ d (simbolo)´ The positive square root of the variance . |
|
|
84 |
Fascicle II.3 -- Suppl. No. 6 |
2011 observed value (in statistics)
F: valeur observee´ (en statistique)
|
S: valor observado (en estadistica)´ The value of a characteristic | etermined as the result of an observation or test . |
||
|
2012 |
relative frequency F: frequence´ (statistique) S: frecuencia relativa The ratio of the number of times a particular value, or a value falling within a given class, is observed to the total |
number of observations.
2013 statistical test
F: test (statistique)
S: prueba estadistica´
A procedure that is intended to decide whether a hypothesis about the distribution of one or more populations should be rejected or not rejected (accepted).
Note 1 -- The decision taken is a result of the value of an appropriate statistic | r statistics , calculated from values observed in samples taken from the populations under consideration. As the value of the statistic is subject to random variations, there is some risk of error when the decision is taken.
Note 2 -- It is important to note that, generally speaking, a test | ssumes a priori | hat certain assumptions are fulfilled (for example, assumption of independence of the observations, assumption of normality, etc.). These assumptions serve as a basis of the test .
2014 one-sided test
F: test unilateral´
S: prueba unilateral
A statistical test | n which the statistic | sed is one-dimensional and the critical region is the set of values lower than, or the set of values greater than, a given number.
2015 two-sided test
F: test bilateral´
S: prueba bilateral
A statistical test | n which the statistic | sed is one-dimensional and in which the critical region is the set of values lower than a first given number and the set of values greater than a second given number.
2016 null hypothesis, H¯0 (symbol)
Fascicle II.3 -- Suppl. No. 6 85
S: hipotesis´ nula, H0(simbolo)´
The hypothesis to be rejected or not rejected (accepted) at the outcome of the statistical test . 2017 alternative hypothesis, H¯1 (symbol)
S: hipotesis´ alternativa, H1 | simbolo)´
The hypothesis, usually composite, which is opposed to the null hypothesis
86 Fascicle II.3 -- Suppl. No. 6
2018 critical region
F: region´ critique
S: region´ critica´
The set of possible values of the statistic | sed such that, if the value of the statistic | hich results from the observed values belongs to the set, the null hypothesis will be rejected, whereas it will not be rejected (accepted) if the opposite is the case.
2019 critical values
F: valeurs critiques
S: valores criticos´
The given value(s) which limit the critical region .
2020 error of the first kind
S: error de primera clase
The error | ommitted in rejecting the null hypothesis , because the statistic | akes a value which belongs to the critical region , when the null hypothesis is true.
2021 type I risk
S: riesgo de tipo I
The probability | f committing the error of the first kind , which varies according to the real situation (within the framework of the null hypothesis ). Its maximum value is the significance level of the statistical test .
2022 error of the second kind
S: error de segunda clase
The error | ommitted in failing to reject (accept) the null hypothesis | because the value of the statistic does not belong to the critical region ), when the null hypothesis is not true (the alternative hypothesis therefore being true).
2023 type II risk
S: riesgo de tipo II
The probability , designated b, of committing the error of the second kind . Its value depends on the real situation and can only be calculated if the alternative hypothesis is adequately specified.
Fascicle II.3 -- Suppl. No. 6 87
2024 operating characteristic curve; OC curve (for a statistical test plan)
F: courbe d'efficacite´ (d'un plan de test)
S: curva caracteristica´ de funcionamiento (para un plan de prueba estadistica)´
A curve showing, for a given statistical test | lan, the probability of acceptance | s a function of the actual value of a given measure .
88 Fascicle II.3 -- Suppl. No. 6
2025 producer's risk (point)
F: (point du) risque du fournisseur
S: (punto de) riesgo del proveedor
A point on the operating characteristic curve | orresponding to some predetermined and usually low probability of rejection .
2026 consumer's risk (point)
F: (point du) risque du client
S: (punto de) riesgo del consumidor
A point on the operating characteristic curve | orresponding to a predetermined and usually low probability of acceptance .
2027 power of the test
F: puissance du test
S: potencia de la prueba
The probability | f not committing the error of the second kind , equal to 1 | (em | (*a, and thus the probability of rejecting the null hypothesis when this hypothesis is false.
2028 significance level (of a statistical test), a (symbol)
F: niveau de signification (d'un test); seuil de signification, a | (symbole)
S: nivel de significacion´ (de una prueba estadistica);´ umbral de significacion,´ a | (simbolo)´
The given value which limits the probability | f the null hypothesis | eing rejected, if the null hypothesis is true.
Note -- The critical region | s determined in such a way that if the null hypothesis | s true, the probability of this null hypothesis being rejected should be not more than this given value.
2029 probability of acceptance
F: probabilite´ d'acceptation
|
S: probabilidad de aceptacion´ The probability | hat an item | ill be accepted by a given statistical test | lan. |
|||
|
2030 |
probability of rejection F: probabilite´ de rejet S: probabilidad de rechazo The probability | hat an item | ill not be accepted by a given statistical test | lan. |
||
|
2031 |
confidence interval Fascicle II.3 -- Suppl. |
No. 6 89 |
F: intervalle de confiance
S: intervalo de confianza
The random interval limited by two statistics | r by a single statistic , such that the probability that a parameter to be estimated is covered by this interval is equal to a given value 1 | (em | (*a, where a is the significance level .
90 Fascicle II.3 -- Suppl. No. 6
2032 statistical tolerance interval
F: intervalle statistique de dispersion
S: intervalo estadistico´ de tolerancia
A random interval limited by two statistics | r by a single statistic , such that the probability that a fraction of the population, equal to or greater than a given value between 0 and 1, is covered by this interval is equal to a given value 1 | (em | (*a, where a is the significance level .
2033 confidence limit
F: limite de confiance
S: limite´ de confianza
Each of the limits of a two-sided confidence interval , or the single limit of a one-sided confidence interval .
2034 estimation
S: estimacion´ (de parametros)´
The operation made for the purpose of assigning, from the observed values in a sample, numerical values to the parameters of the distribution chosen as the statistical model of the population from which this sample is taken.
2035 estimate
F: estimation
S: estimacion´
The result of an estimation .
Note -- This result may be expressed either as a single numerical value (point estimation) or as a confidence interval .
2036 estimator
F: estimateur
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S: estimador A statistic | ntended to estimate a population parameter. |
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2037 |
confidence coefficient; confidence level F: niveau de confiance S: coeficiente de confianza; nivel de confianza The value 1 | (em | (*a of the probability | ssociated with a confidence interval | r a statistical tolerance interval |
, where a is the significance level .
Fascicle II.3 -- Suppl. No. 6 91
2038 statistic
F: statistique
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S: estadistico´ A function of the observed values | erived from a sample. |
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2039 |
acceptable level (of a measure) F: niveau acceptable (d'une caracteristique)´ S: nivel aceptable (de una medida) A level for a measure | f a given performance which in a test |
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ANNEX A Alphabetical list of definitions contained in this |
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2 col 9107 2039 |
accelerated test acceptable level |
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7209 3010 7107 7103 7106 9302 7107 7109 5209 5311 2017 8105 8106 8107 8108 6012 8105 4002 1007 5102 9502 5509 5212 5212 2001 7113 9102 |
accumulated down time accumulated time active corrective maintenance time active maintenance time active preventive maintenance time active redundancy active repair time administrative delay ageing failure ageing fault alternative hypothesis asymptotic availability asymptotic unavailability asymptotic mean availability asymptotic mean unavailability automatic maintenance availability availability performance average (deprecated) bug burn in busy state cataleptic failure catastrophic failure (deprecated) characteristic check-out time compliance test |
Fascicle II.3 -- Suppl. No. 6 93 |
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5314 2037 2031 2037 2033 7307 7308 2026 6023 6005 7105 5103 5108 5202 5302 94 |
complete confidence confidence confidence confidence constant constant consumer's controlled corrective corrective critical critical critical critical Fascicle |
complete fault confidence coefficient confidence interval confidence level confidence limit constant failure intensity period constant failure rate period consumer's risk (point) controlled maintenance corrective maintenance corrective maintenance time critical defect critical defective item critical failure critical fault II.3 -- Suppl. No. 6 |
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2018 5510 2019 5313 5101 5107 5107 6006 5211 4001 5111 5207 5309 5318 9103 5219 5505 7207 2005 5507 7208 5211 4006 3009 7306 6020 9106 3001 5401 5505 2020 2022 2035 1004 |
critical region critical state critical value data sensitive fault defect defective defective item deferred maintenance degradation failure dependability design defect design failure design fault determinate fault determination test deterministic failure disabled state disabled time distribution function down state down time drift failure durability duration early failure period elementary maintenance activity endurance test entity error error (deprecated sense) error of the first kind error of the second kind estimate estimated . | | |
Fascicle II.3 -- Suppl. No. 6 95 |
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2034 2036 5402 2008 5506 7210 7210 1003 9304 5201 96 |
estimation estimator execution expectation external external external extrapolated fail failure Fascicle |
estimation estimator execution error expectation external disabled state external disabled time external loss time extrapolated . | | fail safe failure II.3 -- Suppl. No. 6 |
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5217 8204 8210 5218 5322 8202 8209 5301 9411 6027 7111 8311 6025 6026 7114 6024 7114 9306 5322 9404 9403 6024 9305 9408 9405 5323 9203 6009 9105 9403 9404 5504 7206 9405 |
failure cause failure intensity failure intensity acceleration factor failure mechanism failure mode (deprecated) failure rate failure rate acceleration factor fault fault analysis fault correction fault correction time fault coverage fault diagnosis fault localization fault localization time fault location (deprecated) fault location time (deprecated) fault masking fault mode fault modes, effects and criticality analysis (FMECA) fault modes and effects analysis (FMEA) fault recognition fault tolerance fault tree fault tree analysis (FTA) faulty field data field maintenance field test FMEA (fault modes and effects analysis) FMECA (fault modes, effects and criticality analysis) free state free time FTA (fault tree analysis) |
Fascicle II.3 -- Suppl. No. 6 97 |
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6013 6028 6015 6016 5314 6014 3006 5402 5211 5504 7206 5106 6019 5319 5206 98 |
function function function-degrading function function function-preventing functional generated gradual idle idle imperfection indenture indeterminate inherent Fascicle |
function affecting maintenance function check-out function-degrading maintenance function permitting maintenance function preventing fault function-preventing maintenance functional mode generated error gradual failure idle state idle time imperfection indenture level indeterminate fault inherent weakness failure II.3 -- Suppl. No. 6 |
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1005 5308 6009 3007 1009 8101 8111 8204 8202 8302 8102 5403 5317 5507 1005 3001 9104 5320 9501 6017 6018 7110 8301 9415 9415 9112 9412 4004 9413 9506 9111 6003 6021 6018 |
inherent . | | inherent weakness fault in situ maintenance instant of time instantaneous . | | instantaneous availability instantaneous availability of a leased circuit instantaneous failure intensity instantaneous failure rate instantaneous repair rate instantaneous unavailability interaction error intermittent fault internal disabled state intrinsic . | | item laboratory test latent fault learning process level of maintenance line of maintenance logistic delay maintainability maintainability allocation maintainability apportionment maintainability demonstration maintainability model maintainability performance maintainability prediction maintainability programme maintainability verification maintenance maintenance action maintenance echelon |
Fascicle II.3 -- Suppl. No. 6 99 |
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6030 7102 6001 6002 4005 6021 7101 9414 5105 5109 5304 5112 5208 5310 8110 8308 8401 8305 2008 1007 8110 8308 100 |
maintenance maintenance maintenance maintenance maintenance maintenance maintenance maintenance major major major manufacturing manufacturing manufacturing MADT MART MAD MDT mean mean mean mean Fascicle |
maintenance entity maintenance man-hours (MMH) maintenance philosophy maintenance policy maintenance support performance maintenance task maintenance time maintenance tree major defect major defective item major fault manufacturing defect manufacturing failure manufacturing fault MADT (mean accumulated down time) MART (mean active repair time) MAD (mean administrative delay) MDT (mean down time) mean mean . | | mean accumulated down time (MADT) mean active repair time (MART) II.3 -- Suppl. No. 6 |
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8401 8103 8305 8203 8205 8403 8304 8303 8306 8208 8207 8206 8310 8310 8310 8104 8109 3011 5106 5110 5305 5205 5307 5405 5204 5306 8403 7102 8306 8208 8207 8206 8310 8109 |
mean administrative delay (MAD) mean availability mean down time (MDT) mean failure rate mean failure intensity mean logistic delay (MLD) mean maintenance man-hours mean repair rate mean repair time (MRT) mean time between failures (MTBF) mean time to failure (MTTF) mean time to first failure (MTTFF) mean time to recovery mean time to repair (deprecated) mean time to restoration (MTTR) mean unavailability mean up time (MUT) measure minor defect minor defective item minor fault mishandling failure mishandling fault mistake misuse failure misuse fault MLD (mean logistic delay) MMH (maintenance man-hours) MRT (mean repair time) MTBF (mean time between failures) MTTF (mean time to failure) MTTFF (mean time to first failure) MTTR MUT (mean up time) |
Fascicle II.3 -- Suppl. No. 6 101 |
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3013 5104 5203 5303 5214 3003 5502 7202 7204 2016 102 |
modification non-critical non-critical non-critical non-relevant non-repaired non-operating non-operating non-required null Fascicle |
modification non-critical defect non-critical failure non-critical fault non-relevant failure non-repaired item non-operating state non-operating time non-required time null hypothesis II.3 -- Suppl. No. |
6 |
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9201 2011 2024 6010 2014 6009 2024 5501 7201 3012 1006 5505 5315 5316 5316 2007 1008 8309 8402 8404 8307 8101 8102 2027 1002 9401 6004 7104 5215 2002 2006 2029 2030 2025 |
observed data observed value OC curve off-site maintenance one-sided test on-site maintenance operating characteristic curve operating state operating time operation operational . | | outage partial fault permanent fault persistent fault p-fractile (of a probability distribution) p-fractile . | | p-fractile active repair time p-fractile administrative delay p-fractile logistic delay p-fractile repair time pointwise availability pointwise unavailability power of the test predicted . | | prediction preventive maintenance preventive maintenance time primary failure probability probability density function probability of acceptance probability of rejection producer's risk (point) |
Fascicle II.3 -- Suppl. No. 6 103 |
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5312 5404 2007 2004 2003 6029 9301 9204 8201 9407 9503 9504 9402 4003 2012 5213 104 |
programme-sensitive propagated p-quantile random random recovery redundancy reference reliability reliability reliability reliability reliability reliability relative relevant Fascicle |
programme-sensitive fault propagated error p-quantile random process random variable recovery redundancy reference data reliability reliability block diagram reliability growth reliability improvement reliability model reliability performance relative frequency relevant failure II.3 -- Suppl. No. 6 |
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6011 6005 8312 8302 7105 3002 5219 3005 7203 6029 6007 5216 9109 2028 5316 2010 9303 5503 7205 9409 2038 2013 2032 8105 9108 9406 9410 5210 6001 5219 |
remote maintenance repair repair coverage repair rate repair time repaired item reproducible failure required function required time restoration scheduled maintenance secondary failure screening test significance level solid fault standard deviation standby redundancy standby state standby time state-transition diagram statistic statistical test statistical tolerance interval steady-state availability step stress test stress analysis stress model sudden failure supervision systematic failure |
Fascicle II.3 -- Suppl. No. 6 105 |
Blanc
106 Fascicle II.3 -- Suppl. No. 6
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5321 7112 9101 9202 9110 7303 3009 7302 7301 3008 7304 7304 5317 1001 2015 2021 2023 7108 5508 7211 6008 7305 2009 9203 5317 5206 5308 5209 5311 7309 |
systematic fault technical delay test test data time acceleration factor time between failures time duration time to failure time to first failure time interval time to recovery time to restoration transient fault true . | | two-sided test type I risk type II risk undetected fault time up state up time unscheduled maintenance useful life variance variate volatile fault weakness failure weakness fault wearout failure wearout fault wear-out failure period |
Fascicle II.3 -- Suppl. No. 6 107 |
Blanc
108 Fascicle II.3 -- Suppl. No. 6
ANNEX B
(to Supplement 6, Part I)
Relations between defect, failure and fault concepts
H.T. [T1.6]
TABLE B-1
center box; cw(72p) | cw(78p) | cw(78p) . Defect Failure Fault _ lw(72p) | lw(78p) | lw(78p) . Critical defect Critical failure Critical fault lw(72p) | lw(78p) | lw(78p) . Non-critical defect Non-critical failure Non-critical fault lw(72p) | lw(78p) | lw(78p) . Major defect -- Major fault lw(72p) | lw(78p) | lw(78p) . Minor defect -- Minor fault lw(72p) | lw(78p) | lw(78p) . -- Misuse failure Misuse fault lw(72p) | lw(78p) | lw(78p) . -- Mishandling failure Mishandling fault lw(72p) | lw(78p) | lw(78p) . -- Inherent weakness failure Inherent weakness fault lw(72p) | lw(78p) | lw(78p) . Design defect Design failure Design fault lw(72p) | lw(78p) | lw(78p) . Manufacturing defect Manufacturing failure Manufacturing fault lw(72p) | lw(78p) | lw(78p) . -- Ageing failure Ageing fault lw(72p) | lw(78p) | lw(78p) . -- Sudden failure -- lw(72p) | lw(78p) | lw(78p) . -- Gradual failure -- lw(72p) | lw(78p) | lw(78p) . -- Cataleptic failure -- lw(72p) | lw(78p) | lw(78p) . -- Relevant failure -- lw(72p) | lw(78p) | lw(78p) . -- Non-relevant failure -- lw(72p) | lw(78p) | lw(78p) . -- Primary failure -- lw(72p) | lw(78p) | lw(78p) . -- Secondary failure -- lw(72p) | lw(78p) | lw(78p) . -- Failure cause -- lw(72p) | lw(78p) | lw(78p) . -- Failure mechanism -- lw(72p) | lw(78p) | lw(78p) . -- -- Programme-sensitive fault lw(72p) | lw(78p) | lw(78p) . -- -- Data-sensitive fault lw(72p) | lw(78p) | lw(78p) . -- -- Complete fault lw(72p) | lw(78p) | lw(78p) . -- -- Partial fault lw(72p) | lw(78p) | lw(78p) . -- -- Persistent fault lw(72p) | lw(78p) | lw(78p) . -- -- Intermittent fault lw(72p) | lw(78p) | lw(78p) . -- -- Fault mode lw(72p) | lw(78p) | lw(78p) . -- -- Determinate fault lw(72p) | lw(78p) | lw(78p) . -- -- Indeterminate fault lw(72p) | lw(78p) | lw(78p) . -- -- Latent fault lw(72p) | lw(78p) | lw(78p) . -- Systematic failure Systematic fault lw(72p) | lw(78p) | lw(78p) . Bug -- -- _
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Table |
Table B-1/Sup. 6 [T1.6], p. |
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Fascicle II.3 -- Suppl. No. 6 |
109 |
ANNEX C
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(to Supplement 6, Part I) List of recommended symbols and abbreviations |
a Significance level
b Type II risk
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l(t ) Instantaneous failure rate l (t |
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1, | fIt2) Mean failure rate [in time interval (t1, | fIt2)] |
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m(t ) Instantaneous repair rate m | (t |
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1, | fIt2) Mean repair rate [in time interval (t1, | fIt2)] |
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d Standard deviation A Asymptotic availability A (t ) Instantaneous availability A | Asymptotic mean availability A | (t |
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1, | fIt2) Mean availability [in time interval (t1, | fIt2)] |
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ASR Answer seizure ratio E (X ) Mean (of X ) f (x ) Probability density function F (x ) Distribution function FMEA Fault modes and effect analysis FMECA Fault modes, effects and criticality analysis FTA Fault tree analysis H |
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0 Null hypothesis |
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H |
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1 Alternative hypothesis |
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MAD Mean administrative delay MADT Mean accumulated down time MART Mean active repair time MDT Mean down time MLD Mean logistic delay MMH Maintenance man-hours MRT Mean repair time MTBF Mean time between failures MTTF Mean time to failure MTTFF Mean time to first failure MTTR Mean time to restoration 110 Fascicle II.3 -- Suppl. No. 6 |
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MUT Mean up time N (t |
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1, t2) Number of failures [in time interval (t1, | fIt2)] |
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R Reliability U Asymptotic unavailability U (t ) Instantaneous unavailability U | Asymptotic mean unavailability U | (t |
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1, | fIt2) Mean unavailability [in time interval (t1, | fIt2 |
2)] |
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z (t ) Instantaneous failure intensity z | (t |
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1, | fIt2) Mean failure intensity [in time interval (t1, | |
fIt2)] |
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Fascicle II.3 -- Suppl. No. 6 111
GUIDE FOR EVALUATING AND IMPLEMENTING | fR ALTERNATE ROUTING
NETWORKS
A systematic procedure consisting of a number of distinct steps is used for the evaluation of alternate routing networks.
These steps are given in the flowchart of Annex A and are provided as guidance. Administrations may wish to expand, delete or change the order of these steps to meet circumstances.
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The steps may be grouped into the following six processes: -- Identification of alternate route. -- Preliminary screening. -- Data gathering. -- Evaluation. -- Implementation. -- Monitoring. |
A terminal Administration selects an alternate route.
A tentative agreement is reached with the opposite terminal Administration to use the selected alternate route, and both terminal Administrations reach tentative agreement with the transit Administration to explore the use of its network as an alternate route.
If no tentative agreements are reached, another alternate route is selected or if none is available, the procedure is abandoned.
Using available data, the organizational elements of the terminal Administrations responsible for transmission, routing and call completion, analyse the feasibility of utilizing the alternate route.
If an objection is raised, another alternate route is selected or, if none is available, the procedure is abandoned.
A questionnaire is issued to all Administrations involved to obtain additional information before an evaluation is made of the proposed alternate route.
The questionnaire can include requests for transmission, routing, call completion rates, traffic profiles, circuit costs, and transit charges.
If there is no response to the questionnaire or if the information provided indicates that the alternate route is unsuitable, another alternate route is selected or, if none is available, the procedure is abandoned.
112 Fascicle II.3 -- Suppl. No. 7
The alternate routing network is dimensioned according to Recommendation E.522.
If additional circuits are required on the alternate route, and the required increment exceeds the available capacity, another alternate route is selected. If no other alternate route is available Administrations may choose to retain the selected alternate route and accept a cost disadvantage.
Fascicle II.3 -- Suppl. No. 7 113
Final negotiations are carried out and approval of all Administrations involved in the alternate route network is sought.
The negotiations would include the reporting procedure and responsibility for recording traffic overflowing to the alternate route.
If final agreement cannot be reached, another alternate route is selected or, if none is available, the procedure is abandoned.
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Traffic volumes |
Traffic volumes and performance data for the alternate route are recorded and exchanged at regular intervals. ANNEX A (to Supplement No. 7) Flowchart of evaluation and implementation procedure for alternate routing networks |
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Figure A-1, p. |
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II.3 -- Suppl. No. 7 |
Figure A-2, p. Fascicle II.3 -- Suppl. No. 7 115
116 Fascicle II.3 -- Suppl. No. 7