Sequencing of Diagnostic Tests for Fault Isolation By Dynamic Programming

This paper presents a new approach to the cost-effective design of fault-isolation procedures. This approach is oriented specifically toward built-in-test (BIT) diagnostic subsystems for modular military electronic equipment. The objective is to minimize the s-expected costs associated with the repair of electronic systems. Two basic problems are analyzed. 1. Determine the sequence of diagnostic tests to be executed automatically by the BIT (following an equipment malfunction) to isolate the group of modules which contains the faulty unit. My original solution is to apply probabilistic dynamic programming which is guaranteed to generate a sequence of tests of minimum s-expected cost 2. Specify a search procedure which minimizes the s-expected cost of secondary isolation, performed semi-automatically or manually, to locate the failed module within a group of modules identified by the BIT primary diagnostic. A search procedure is adapted from the literature to solve this problem. No general conclusions on sequencing of tests have emerged from this work.