Intelligent derating for reliability

An approach to design for reliability based on the formulation of derating criteria, the determination of levels of criticality for derating analysis, and production rule derating is presented. The approach utilizes Prolog procedures to generate a user-definable hierarchy of parts classifications whose working parameters follow user-definable guidelines and constraints. The specific focus is on the Maryland Computer-Aided Life Cycle Engineering (CALCE) derating program, which can be used for many different derating guidelines. Instead of a specific and rigid derating classification of part types, the CALCE derating program allows the user to define and change the derating criteria as needed for the specific derating application. By providing this custom-editing facility, the program can be used to derate electronic components on an electronics circuit board as well as treads on a tank. To do this, the user defines what is being derated and the derating test (rule) criteria