1、 ANSI/VITA 51.0 VITA Copyright VITA 2012. All Rights Reserved. PO Box 19658, Fountain Hills, AZ 85269 480-837-7486 Approved ANSI Standard ANSI/VITA 51.0 2008 (R2012) Reliability Prediction Revision Approved June 2012 Abstract This document provides a framework for electronics equipment reliability
2、 standards, and establishes a reliability Community of Practice. It addresses the limitations of existing prediction practices with a series of subsidiary specifications that contain the “best practices” within industry for performing electronics reliability analysis. The development of VITA 51.0 an
3、d the subsidiary specifications is an effort to give harmony, consistency and repeatability to reliability practices. Revision Approved: June 2012 American National Standards Institute, Inc. Secretariat: VITA ANSI/VITA 51.0 Copyright VITA 2012. All Rights Reserved. Notices American National Standard
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11、SBN 1-885731-46-9. ANSI/VITA 51.0 Copyright VITA 2012. All Rights Reserved. Table of Contents 1 Introduction . 2 1.1 Objectives . 2 1.2 Overview . 2 1.3 Terminology 3 1.3.1 Specification Key Words . 3 1.3.2 Definitions 4 1.4 Normative References - Subsidiary Specifications . 4 1.4.1 General Descript
12、ion . 4 1.4.2 Purpose of Subsidiary Specifications 5 1.5 Non-Normative References 5 2 Overview of Reliability Prediction Methods 6 2.1 Characteristics of Reliability Prediction Methods 6 2.1.1 Parts count versus parts stress . 6 2.1.2 Part types 6 2.1.3 Quality level . 6 2.1.4 Environment 6 2.2 Reli
13、ability Data Sources 6 2.2.1 Field Data 6 2.2.2 Test Data . 7 2.2.3 Manufacturers Test Data 7 2.2.4 Similarity Analysis 7 2.2.5 Modeling essentially a failure is the functional manifestation of a fault or failure mode in the end item application. Failure mechanism The physical, chemical, electrical,
14、 thermal or other process which results in failure. Failure mode The consequence of a fault on device operation, often an abstraction used to represent a common effect of multiple faults (e.g., shorted output, open input, fracture, excessive wear). Hardware The term for a collection of mechanical an
15、d electronic components that performs some system functions. Mean Time Between Failure (MTBF) For a particular interval, the total functioning life of a population of an item divided by the total number of failures within the population during the measurement interval. The definition holds for time,
16、 cycles, miles, events, or other measures of life units. (MIL-STD-721) Reliability The probability that an item will perform its intended function for a specified period under stated operational and environmental conditions. Table 1.3.2-1: Term Definitions 1.4 Normative References - Subsidiary Speci
17、fications This standard is organized in a hierarchy, with this document and sub-tier documents that are referred to as “subsidiary specifications.” This document provides an overview, guidelines and a general purpose standard for failure rate predictions. The subsidiary specifications provide specif
18、ic methods, practices and standard approaches for electronics failure rate predictions. 1.4.1 General Description A subsidiary specification provides detailed methodology practices or approaches to electronics failure rate predictions by using either an existing prediction method or documenting new industry accepted techniques or standards. Each method, practice or approach may be based on existing reliability prediction practices with modifying factors to update these existing standards.
