1、 AEROSPACE RECOMMENDED PRACTICE RMS Terms and Definitions SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particu
2、lar use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2005 SAE Internat
3、ional All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323
4、 (inside USA and Canada) Tel: 724-776-4970 (outside USA) Fax: 724-776-0790 Email: custsvcsae.org SAE WEB ADDRESS: http:/www.sae.org Issued 2005-03 ARP5638 TABLE OF CONTENTS 1. SCOPE 2 2. REFERENCES.2 2.1 SAE Publications2 2.2 Department of Defense Publications3 2.3 Ministry of Defence Publications4
5、2.4 NATO Publications.4 2.5 ISO Publications.5 2.6 Government Organizations 5 2.7 Relilability and Maintainability Symposium (RAMS).5 2.8 American Institute of Aeronautics and Astronautics (AIAA).5 2.9 Publications5 3. APPROACH.6 3.1 Discussion of Data Base Generation .6 3.2 Selection/Recommendation
6、 Process .7 3.2.1 Selection of Terms Applicable to RMS.7 3.2.2 Selection of Recommended Terms7 3.2.3 Selection of Preferred Definitions.7 3.2.4 Consensus Process .8 SAE ARP5638 - 2 - 1. SCOPE: The terms used in most engineering technologies tend to be physical characteristics such as speed, rate of
7、turn, and fuel consumption. While they may require very careful definition and control of the way in which they are measured, the terms themselves are not subject to different interpretations. Reliability, Maintainability, and Supportability (RMS) however, use terms that are defined in a variety of
8、ways with multiple interpretations. The variety of definitions given to a single term creates problems when trying to compare the performance of one system to another. To eliminate the confusion, a literature search that listed current and past RMS terms and definitions was conducted. The literature
9、 search included input from the US Military, UK Military, NATO, SAE, IEEE, NASA, ISO, University Research, and other publications. The object was to determine the common definition of Reliability Terms from a variety of sources. It is accepted that some of the definitions may be unique because of th
10、e nature of the mission, but it is the strong conviction of the Government and Industry practitioners who make up the SAE Reliability Committee under the G-11 Division that there should be some fundamental definitions used for all hardware systems. Accordingly, in October of 2003 the task of develop
11、ing and revising the current SAE AIR4896 publication issued in 1995 of Recommended RMS Terms and Parameters. It is understood by individuals that participated in this project that future editions will update terminology as developments are made within the RMS community. Due to the complexity and nat
12、ure of Software Reliability, we have specifically excluded “software reliability” terms from this edition. Future updates of this document will continue to reflect the converging of defense and commercial technology and standards. 2. REFERENCES: 2.1 SAE Publications: The SAE Standards are available
13、from SAE, Internationals website: http:/www.sae.org. JA1000-1 Reliability Program Standard Implementation Guide JA1002 Software Reliability Program Standard AIR5083 Engineering Probabilistic Methods SAE ARP5638 - 3 - 2.2 Department of Defense Publications: The military references are available from
14、the Acquisition Streamlining and Standardization Information System (ASSIST) at http:/assist.daps.dla.mil/online/start and the DoD Directives Systems at http:/www.dtic.mil/whs.directives. It is recommended that standards are downloaded from DoD Sponsored websites to obtain the current version. Howev
15、er, websites are listed for other online resources that distribute the standards. Military Standards MIL-STD-1309D “Definitions of Terms for Test Measurement and Diagnostic,” Department of Defense, February 12, 1992. MIL-HDBK-338 “Electronic Reliability Design Handbook,” Department of Defense, Octob
16、er 1998. http:/www.reliasoft.org/mil_std/mil_hdbk_338b.pdf MIL-STD-1472F “Human Engineering,” Department of Defense, October 5, 2003. http:/www.reliasoft.org/mil_std/mil_std_1472f.pdf DoD 3110.5 “Materiel Condition Reporting for Mission-Essential Systems and Equipment,” Department of Defense, Septem
17、ber 14, 1990. http:/www.dtic.mil/whs/directives/corres/pdf/i31105_091490/i31105p.pdf OPNAVINST 4790.2D “The Naval Aviation Maintenance Program,” Department of Defense, April 11, 2001. http:/logistics.navair.navy.mil/4790 Military Standards with Superceding Document MIL-STD-1388-1A “Logistic Support
18、Analysis,” Department of Defense, April 11, 1983. Superceded by MIL-HDBK-502, “Acquisition Logistics,” May 30, 1997. http:/ . MIL-STD-471A “Maintainability Verification/Demonstration/Evaluation,” 6/12/1995. http:/www.reliasoft.org/mil_std/mil_std_471a.pdf Superceded by MIL-HDBK-470A, “Designing and
19、Developing Maintainable Products and Systems, Volume I and Volume II,” Aug 4, 1997. http:/assist.daps.dla.mil/docimages/0000/91/99/MAIN.PD5 SAE ARP5638 - 4 - 2.2 (Continued): Military Standards Inactive MIL-STD-721C “Definitions of Terms for Reliability and Maintainability,” Department of Defense, J
20、une 12, 1981. http:/www.reliasoft.org/mil_std/mil_std_721c.pdf MIL-STD-785B “Military Standard Reliability Program for Systems and Equipment Development and Production,” Department of Defense, September 15, 1980. http:/www.reliasoft.org/mil_std/mil_std_785b.pdf MIL-STD-1843 USAF “Reliability-Centere
21、d Maintenance for Aircraft, Engines MART is Mean Active Repair Time ARMP-7 Defence Standard 00-40 Availability, Operational The probability that an equipment/system at any instant in the required operating time will operate satisfactorily under stated conditions where the time considered includes op
22、erating, corrective and preventive maintenance, administrative delay time and logistic delay time. ARMP-7 Defence Standard 00-40 NHB 5300.4(1G) Axis-Orthogonal Simulation A method for updating First-Order Reliability Method/Second-Order Reliability Method results. NOTE: This is a complex concept. Fo
23、r more detailed information further references should be sought. AIR5083 Bayesian Approach A method of statistical inference with a focus on subjective probability used primarily when limited data is available to determine the distribution of a system. NOTE: This is a complex concept. For more detai
24、led information further references should be sought. AIR5083 Built-in Test Equipment BITE Any device permanently mounted in the equipment and used for the express purpose of testing the equipment, either independently or in association with external test equipment. ARMP-7 Built-In-Test BIT An integr
25、al capability of the equipment which provides an on-board test capability to detect, diagnose, or isolate system failures down to the LRU level, if possible. The fault detection and, possibly, isolation capability is used for periodic or continuous monitoring of a systems operational health, and for
26、 observation and, possibly, diagnosis as a prelude to maintenance action. ARMP-7 Burn-In The operation of an item to stabilize its characteristics. Basically, a reliability conditioning procedure which is a method of ageing an item by operating it under specified environmental and test conditions in
27、 accordance with an established procedure in order to eliminate early failures and age or stabilize the item prior to final test and shipment. ARMP-7 Calibrate To determine and make required corrections in calibration standards or Precision Measuring Equipment (PME). It consists of the comparison of
28、 two instruments, one of which is a certified calibration standard of known accuracy, to detect and adjust any discrepancy in the accuracy of the other instrument or PME being compared with the certified calibration standard. OPNAVINST 4790.2D SAE ARP5638 - 11 - Term Acronym Definition Formula Refer
29、ence Common(Critical)Failure Mode Failures of distinct components caused by a common initiating event ARMP-7 Concurrent Engineering A systematic approach to the integrated, concurrent design of products and their related processes, including manufacture and support. This approach is intended to caus
30、e the developers, from the outset, to consider all elements of the product life cycle from conception through disposal, including quality, cost, schedule and user requirements. ARMP-7 Confidence Level That probability that a given statement is true. The statement in question normally refers to wheth
31、er a given parameter lies between two limits, is above a lower limit, or is below an upper limit. ARMP-7 Confidence Test (1) A test performed to provide a high degree of certainty that the unit under test (UUT) is operating acceptably. (2) A check of the performance of all test system stimulus and m
32、easurement functions, to detect degradation with respect to system specifications, and to inform the system operator. MIL-STD-1309D Configuration Control The establishment of an agreed build standard for an item and the procedure for controlling change to that standard, in order that it may be defin
33、ed at any time. ARMP-7 NAVAIR 01-1A-32 Consumers Risk The probability of accepting equipment with a true mean time between failure (MTBF) equal to the lower test MTBF. The probability of accepting equipment with a true MTBF less than the lower test MTBF will be less than the consumers ARMP-7 Contrac
34、tor Data Requirements List A contractual term which refers to all the written documents (i.e. reports, drawings, procedures, data) which a contractor is obligated, under the contract, to provide to the procuring activity. This is over and above any hardware or services which the contractor may be al
35、so obligated to provide. ARMP-7 Corrective Action Action taken to eliminate the causes of an existing non conformity, defect or other undesirable situation in order to prevent recurrence. ARMP-7 Critical Defect A critical defect is a defect that judgment and experience indicate is likely to result i
36、n hazardous or unsafe conditions for individuals using, maintaining, or depending upon the product; or a defect that judgment and experience indicate is likely to prevent performance of the tactical function of a major end item such as an aircraft or missile. NAVAIR 01-1A-32 Critical Item An item wh
37、ose failure could result in a critical failure or that requires special effort during development/production. ARMP-7 Criticality A relative measure of the consequence of a failure mode and itsfrequency of occurrences. MIL-STD-721C SAE ARP5638 - 12 - Term Acronym Definition Formula Reference De-Buggi
38、ng A process to detect and remedy inadequacies, preferably prior to operational use. During this period, defective parts and workmanship errors are identified and corrected under test conditions that closely simulate field operational stresses. MIL-STD-721C NAVAIR 01-1A-32 Defect Any non-conformance
39、 of an item with specified requirements, or a condition which experience indicates could result in a non-conformance. ARMP-7 Degradation A gradual impairment in ability to perform. MIL-STD-721C Delay Time That element of down time during which no maintenance is being accomplished on the item because
40、 of either supply or administrative delay MIL-STD-721C Demonstrated That which has been measured by the use of objective evidence gathered under specified conditions. MIL-STD-721C Dependability A measure of the degree to which an item is operable and capable of performing its required function at an
41、y (random) time during a specified mission profile, given item availability at the start of the mission. (Item state during a mission includes the combined effects of the mission-related system R b. movement, evacuation and hospitalization of personnel; c. acquisition or construction, maintenance, o
42、peration and disposition of facilities; and d. acquisition of furnishing of services. ARMP-7 SAE ARP5638 - 19 - Term Acronym Definition Formula Reference Low Cycle Fatigue LCF A fatigue cracking failure mode that is defined by the frequency and characteristics of the loading that causes the crack. L
43、CF is caused by stresses built up by mechanical/thermal cycles which occur only a few times per flight. The four most significant LCF events are stop/start/stop cycles, rapid major changes in operating temperature, rapid major changes in rotational speed, and significant increases in aerodynamic loa
44、ding of the blades/disks. There is a cumulative effect of the stresses imposed by these cycles/time since new. OPNAVINST 4790.2D Maintainability The measure of the availability of an item to be retained in or restored to specified condition when maintenance is performed by personnel having specified
45、 skill levels, using prescribed procedures and resources, at each prescribed level of maintenance and repair. Included in this time is not only the time to diagnose the failure and complete the repair, but also the time to obtain the necessary spares and the availability of skilled manpower (Adminis
46、trative or Logistic Delay Time). MIL-STD-721C Defence Standard 00-40 Maintainability Prediction An activity performed with the intention of forecasting the numerical values of a maintainability performance measure of an item, taking into account the maintainability performance and reliability perfor
47、mance measures of its sub-items, under given operational and maintenance condition. ARMP-7 Maintainability Verification A procedure applied for the purpose of determining whether the requirements for maintainability performance measures for an item have been achieved or not. NOTE: The procedure may
48、range from analysis of appropriate data to a maintainability demonstration. ARMP-7 Maintainability, Inherent The maintainability potential present in a design, i.e. the maintainability which is dependent solely on the quality of design and assumes perfect quality of manufacture and correct use in th
49、e field. ARMP-7 Maintainability, Mission The measure of the ability of an item to be retained in or restored to specified condition when maintenance is performed during the course of a specified mission profile. MIL-STD-721C Maintenance 1. All action taken to retain materiel in or to restore it to a specified condition. It includes inspection, testing, servicing, classification as to serviceability, repair, rebuilding and reclamation. 2. All supply and repair action taken to keep
