Chapter 4.1 - General Methodology

Abstract

This chapter overviews all the various activities that are needed for the assessment of the expected service life of a component and its materials in a given application. Systematic approaches to service life predictions of components and materials are needed so that all essential aspects of the problem will be taken into consideration. In almost all existing systematic methodologies for service life prediction, four basic themes appear: (a) performance analysis; (b) failure analysis; (c) laboratory aging testing; and (d) mathematical modeling for service life prediction. In one such general approach to service life prediction, predictive failure modes and effect analysis (FMEA) serves as the starting point for service life prediction from accelerated life test results. The proposed methodology includes three main steps: (a) initial risk analysis of potential failure modes; (b) qualification and screening testing and analysis for service life prediction; and (c) service life prediction involving mathematical modeling and life testing. In the last step also procedures for validating predicted service life from long-term in-service testing are also needed.