How to Check If It Is Safe Not to Retest a Component

Abstract

This paper focuses on ways to reduce testing effort and costs associated with technology-advancement upgrades to systems with open architectures. This situation is common in Navy and DoD contexts such as submarine, aircraft carrier, and airframe systems, and accounts for a substantial fraction of the testing effort. This paper describes methods for determining when testing of unmodified components can be reduced or avoided, and it outlines some methods for choosing test cases efficiently to focus retesting where it is needed, given information about past testing of the same component. Changes to the environment of a system can affect its reliability, even if the behavior of the system remains unchanged. The new capabilities added by a technology upgrade can interact with previously existing capabilities, changing the frequency of their usage as well as the range of input values and, hence, changing their effect on overall system reliability.