1、BSI Standards PublicationBS EN 16602-30-09:2014Space product assurance Availability analysisBS EN 16602-30-09:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN16602-30-09:2014.The UK participation in its preparation was entrusted to TechnicalCommittee ACE/68,
2、 Space systems and operations.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2
3、014. Published by BSI StandardsLimited 2014ISBN 978 0 580 84239 9ICS 49.140Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2014.Amendments issued sinc
4、e publicationDate Text affectedBS EN 16602-30-09:2014EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16602-30-09 September 2014 ICS 49.140 English version Space product assurance - Availability analysis Assurance produit des projets spatiaux - Analyse de disponibilit Raumfahrtproduktsicherung -
5、 Verfgbarkeitsanalyse This European Standard was approved by CEN on 6 March 2014. CEN and CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-dat
6、e lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN and CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by
7、translation under the responsibility of a CEN and CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgiu
8、m, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerl
9、and, Turkey and United Kingdom. CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN/CENELEC All rights of exploitation in any form and by any means reserved worldwide for CEN national Members and for CENELEC Members. Ref. No. EN 16602-30-09:2014 EBS EN 16602-30-09:2014EN 16602-
10、30-09:2014 (E) 2 Table of contents Foreword 4 1 Scope . 5 2 Normative references . 6 3 Terms, definitions and abbreviated terms 7 3.1 Terms from other standards 7 3.2 Terms specific to the present standard . 7 3.3 Abbreviated terms. 10 4 Objectives of availability analysis . 11 5 Specifying availabi
11、lity and the use of metrics . 12 5.1 General . 12 5.1.1 Introduction . 12 5.1.2 Availability requirements . 12 5.2 Different ways of specifying availability . 13 5.2.1 Probability figure convention . 13 5.2.2 Availability during mission lifetime for a specified service 13 5.2.3 Availability at a spe
12、cific time (or time interval) for a specified service 14 5.2.4 Percentage or number of successfully delivered products . 15 5.2.5 Outage probability distribution . 15 5.3 Metrics commonly used 16 5.4 Metrics mapping . 16 5.4.1 General . 16 5.4.2 Metrics mapping at system or subsystem level . 16 5.4.
13、3 Metrics mapping at equipment level 17 6 Availability assessment process 18 6.1 Overview of the assessment process 18 6.2 Availability allocation . 19 6.3 Iterative availability assessment 20 6.4 Availability report content 22 BS EN 16602-30-09:2014EN 16602-30-09:2014 (E) 3 7 Implementation of avai
14、lability analysis 23 7.1 Overview 23 7.2 Availability activities and programme phases )23 7.2.1 Feasibility phase (Phase A) . 23 7.2.2 Preliminary definition phase (Phase B) 24 7.2.3 Detailed definition and production phases (Phase C/D) 24 7.2.4 Utilization phase (Phase E) . 25 Annex A (informative)
15、 Suitable methods for availability assessment . 26 A.1 Overview 26 A.2 Analytical method . 26 A.3 Markov process 27 A.4 Monte-Carlo simulation . 28 Annex B (informative) Typical work package description for availability activities . 29 Bibliography . 30 Figures Figure 3-1: Relations between the vari
16、ous values that characterize the reliability, maintainability and availability of equipment . 8 Figure 6-1: Availability assessment process . 19 Figure 6-2: Example of a dynamic behaviour model . 21 Figure A-1 : Basic availability formulae . 27 Figure A-2 : Example of Markov graph . 28 Figure A-3 :
17、Example of Petri net modelling 28 Tables Table 5-1 Availability and supporting metrics applicable at system and subsystem level . 17 BS EN 16602-30-09:2014EN 16602-30-09:2014 (E) 4 Foreword This document (EN 16602-30-09:2014) has been prepared by Technical Committee CEN/CLC/TC 5 “Space”, the secreta
18、riat of which is held by DIN. This standard (EN 16602-30-09:2014) originates from ECSS-Q-ST-30-09C. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2015, and conflicting national standards s
19、hall be withdrawn at the latest by March 2015. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a
20、 mandate given to CEN by the European Commission and the European Free Trade Association. This document has been developed to cover specifically space systems and has therefore precedence over any EN covering the same scope but with a wider domain of applicability (e.g. : aerospace). According to th
21、e CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, H
22、ungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 16602-30-09:2014EN 16602-30-09:2014 (E) 5 1 Scope This Standard is part of a series of ECSS Stan
23、dards belonging to ECSS-Q-ST-30, Space product assurance Dependability. The present standard defines the requirements on availability activities and provides where necessary guidelines to support, plan and implement the activities. It defines the requirement typology that is followed, with regard to
24、 the availability of space systems or subsystems in order to meet the mission performance and needs according to the dependability and safety principles and objectives. This Standard also describes the process that is followed and the most significant methodologies for the availability analysis to c
25、over such aspects as evaluation of the space element or system availability figure, allocation of the requirement at lower level, and outputs to be provided. This Standard applies to all elements of a space project (flight and ground segments), where Availability analyses are part of the dependabili
26、ty programme, providing inputs for the system concept definition and design development. The on-ground activities and the operational phases are considered, for availability purposes, in order to acquire additional information essential for a better system model finalization and evaluation, and moni
27、tor the system behaviour to optimize its operational performance and improve the availability model for future applications. This standard may be tailored for the specific characteristic and constraints of a space project in conformance with ECSS-S-ST-00. BS EN 16602-30-09:2014EN 16602-30-09:2014 (E
28、) 6 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this ECSS Standard. For dated references, subsequent amendments to, or revisions of any of these publications do not apply. However, parties to agreements b
29、ased on this ECSS Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references the latest edition of the publication referred to applies. EN reference Reference in text Title EN 16601-00-01 ECSS-S-ST-00
30、-01 ECSS system Glossary of terms BS EN 16602-30-09:2014EN 16602-30-09:2014 (E) 7 3 Terms, definitions and abbreviated terms 3.1 Terms from other standards For the purpose of this Standard, the terms and definitions from ECSS-S-ST-00-01- apply. 3.2 Terms specific to the present standard 3.2.1 achiev
31、ed availability probability that a system, subsystem or equipment, when used under stated conditions in an ideal support environment operates satisfactorily at a given time NOTE The downtime is associated only to the active preventive and corrective maintenance. 3.2.2 active redundancy every entity
32、is operating and the system can continue to operate without downtime or defects despite the loss of one or more entities 3.2.3 corrective maintenance maintenance performed to restore system hardware integrity following anomalies or equipment problems encountered during system operations 3.2.4 flight
33、 segment product or a set of products intended to be operated in space 3.2.5 ground segment all ground infrastructure elements that are used to support the preparation activities leading up to mission operations, the conduct of mission operations and all post-operational activities 3.2.6 hot redunda
34、ncy redundancy entity is “ON”, but not necessarily in the right configuration to accomplish the function BS EN 16602-30-09:2014EN 16602-30-09:2014 (E) 8 3.2.7 instantaneous availability probability that an item is in a state to perform a required function under given conditions at a given instant in
35、 time, assuming that the required external resources are provided NOTE Preventive maintenance is generally not taken into account for intrinsic availability. 3.2.8 instantaneous availability probability that an item is in a state to perform a required function under given conditions at a given insta
36、nt of time, taking into account the maintenance strategy (spares policy and related in logistic delays and constraints) 3.2.9 lead time (supplier delay) mean time for supplier to provide spares (including shipping time) 3.2.10 logistic delay mean time for human and material maintenance means to be a
37、vailable (call-out time) 3.2.11 mean availability percentage of time that a system, subsystem or equipment, used under stated conditions, without any scheduled or preventive action and with ideal logistical support, operates satisfactorily for a defined time period 3.2.12 mean availability percentag
38、e of defined time period in which a system, subsystem or equipment, operates satisfactorily used under stated conditions in an actual support environment NOTE The down time is relevant to the corrective maintenance, preventive maintenance, logistic and administrative delays. 3.2.13 mean down time me
39、an time between service interruption and service resumption NOTE See Figure 3-1. correct operationtime0initialfailurewaitingstartof workrepairrestartcorrect operationsecondfailureMTTRMDTMTTFMTBFMUTFigure 3-1: Relations between the various values that characterize the reliability, maintainability and
40、 availability of equipment BS EN 16602-30-09:2014EN 16602-30-09:2014 (E) 9 3.2.14 mean time between failures mean time between two consecutive failures 3.2.15 mean time between outages mean time of operation of an entity between two consecutive non-operational phases caused by corrective or preventi
41、ve maintenance activities 3.2.16 mean time to failure mean time of working of an entity before its first failure NOTE Also known as “mean time to first failure” (MTTFF). 3.2.17 mean time to outage mean time of working of an entity before its first outage 3.2.18 mean time to repair mean duration to r
42、epair equipment with human and material maintenance means being available 3.2.19 mean up time mean time of working of an entity after corrective maintenance (covering repair and replacement) 3.2.20 outage state of an item of being unable to perform its required function IEC Multilingual Dictionary:2
43、001 edition NOTE 1 Causes of outages can be failures, upsets or planned and unplanned events. NOTE 2 The failures can be due to cataleptic intrinsic events or external events. 3.2.21 passive redundancy redundancy not activated before necessary NOTE Also knows as “standby redundancy” or “cold redunda
44、ncy”. 3.2.22 preventive maintenance scheduled or on-condition maintenance actions performed on equipment to reduce its probability of failure or degradation NOTE Preventive maintenance is performed to keep the system at designed reliability and safety levels before failure occurrence. 3.2.23 steady-
45、state availability (asymptotic availability) limit, if any, on the instantaneous availability as time approaches infinite BS EN 16602-30-09:2014EN 16602-30-09:2014 (E) 10 3.3 Abbreviated terms For the purpose of this Standard, the abbreviated terms from ECSS-S-ST-00-01 and the following apply: Abbre
46、viations Meaning FMECA failure modes, effects and criticality analysis GPS global positioning system LD logistic delay MDT mean down time MTBF mean time between failures MTBO mean time between outages MTTF mean time to failure MTTFF mean time to first failure MTTO mean time to outage MTTR mean time
47、to repair MUT mean up time NRB nonconformance review board PDF probability density function RAM reliability availability and maintainability SOW statement of work TWT travelling wave tube w.r.t. with respect to BS EN 16602-30-09:2014EN 16602-30-09:2014 (E) 11 4 Objectives of availability analysis Th
48、e availability analysis is developed in order to verify the conformance of the selected system design with the applicable availability requirements, and provide inputs to estimate the life cycle cost of the system. The above design activity leads to the optimization of the system concept definition
49、with respect to design baseline, operations and logistics provisions. The availability analysis identifies the unavailability contributors in order to quantify their impact in supporting the decision making process, and risk evaluation, reduction and control (see ECSS-M-ST-80). The availability activity is fully integrated into the development programme to ensure the correct support to the other disciplines (e.g. engineering, operations and logistics). BS EN 16602-30-09:2014EN 16602-30-09:2014 (E) 12 5 Specifying availability and the use of metrics 5.1 General
