IEC 61014:2003 pdf – Programmes for reliability growth

IEC 61014:2003 pdf – Programmes for reliability growth.
1 Scope This International Standard specifies requirements and gives guidelines for the exposure and removal of weaknesses in hardware and software items for the purpose of reliability growth. It applies when the product specification calls for a reliability growth programme of equipment (electronic, electromechanical and mechanical hardware as well as software) or when it is known that the design is unlikely to meet the requirements without improvement. A statement of the basic concepts is followed by descriptions of the management, planning, testing (laboratory or field), failure analysis and corrective techniques required. Mathematical modelling, to estimate the level of reliability achieved, is outlined briefly. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60300-1, Dependability management – Part 1: Dependability management systems 1 IEC 60300-2, Dependability management – Part 2: Guidance for dependability programme management 2 IEC 60300-3-1, Dependability management – Part 3-1: Application guide – Analysis tech- niques for dependability – Guide on methodology IEC 60300-3-5:2001, Dependability management – Part 3-5: Application guide – Reliability test conditions and statistical test principles IEC 60605-2, Equipment reliability testing – Part 2: Design of test cycles IEC 60605-3 (all parts), Equipment reliability testing – Part 3: Preferred test conditions IEC 60605-4, Equipment reliability testing – Part 4: Statistical procedures for exponential distribution – Point estimates, confidence intervals, prediction intervals and tolerance intervals IEC 60812, Analysis techniques for system reliability – Procedure for failure mode and effects analysis (FMEA)
3 Terms and definitions For the purposes of this document, the following terms and definitions apply. NOTE 1 Certain terms come from IEC 60050(191) and, where this is the case, the concept from that publication is referenced in square brackets after the definition. ISO 9000:2000 is used as referenced to quality vocabulary. NOTE 2 For analysis of the reliability growth test data, it is important to distinguish between the terms “failure intensity” (for repaired items) and “failure rate” or “instantaneous failure rate” (for non-repaired or one-shot items) defined in IEC 60050(191). 3.1 item entity any part, component, device, subsystem, functional unit, equipment or system that can be individually considered NOTE An item may consist of hardware, software or both, and may also, in particular cases, include people. [IEC 60050, 191-01-01] 3.2 reliability improvement process undertaken with the deliberate intention of improving the reliability performance by eliminating causes of systematic failures and/or by reducing the probability of occurrence of other failures [IEC 60050, 191-17-05] NOTE 1 The method described in this standard is aimed at making corrective modifications aimed at reducing systematic weaknesses or reducing their likelihood of occurrence. NOTE 2 For any item, there are limits to practicable and economic improvement and to achievable growth. 3.3 reliability growth condition characterized by a progressive improvement of a reliability performance measure of an item with time [IEC 60050, 191-17-04] NOTE Modelling (projection) and analysis of reliability improvement during the design phase is based on the standard estimation of the expected product reliability within a given time period. 3.4 integrated reliability engineering engineering tool, consisting of a multitude of reliability/dependability methods integrated into all engineering stages and activities regarding a product, from the conceptual phase through its use in the field by a combination of contributions from all relevant stakeholders
3.14 failure category A systematic failure experienced in test for which management decides not to attempt corrective modification, due to cost, time, technological constraints or other reasons 3.15 failure category B systematic failure experienced in test for which management decides to attempt corrective modification NOTE Failure categorization is not applicable for reliability growth in the product design phase as the view on potential failure modes is entirely different. Here, all components could potentially fail in one mode or another, but the likelihood and consequence of such an event may be very different. Failure modes and their potential causes that may be highly likely to occur are addressed first, and, if resources and schedules allow, other failure modes, less likely to occur, are addressed. A product with a high number of components where each of those might have multiple failure modes, and each of the failure modes might have multiple causes, might require a great amount of effort to classify and then re-classify each of the failure modes or causes, too cumbersome and costly to justify the classification. As the failure classification does not add any value, it is not applied during the reliability growth effort in the product design phase. 3.16 fault state of an item characterized by inability to perform a required function, excluding the inability during preventive maintenance or other planned actions, or due to lack of external resources NOTE A fault is often the result of a failure of the item itself but may exist without prior failure. [IEC 60050, 191-05-01] 3.17 fault mode one of the possible states of a faulty item, for a given required function [IEC 60050, 191-05-22]