A diagnosis assistant for automatic test equipment

Design practice has often not considered either the testability of a piece of manufactured (prime) equipment, or the ease with which testing and diagnostics may be performed on that equipment. This can lead to bottlenecks occurring in the manufacturing process, particularly with the diagnosis of faulty components from functional test failures. The authors present some initial results from the design and building of a program (DIAFAT-diagnosis for automatic test) to assist test engineers in the diagnosis of faulty components on the basis of functional test failures of circuit boards. A model-based approach has been used in the first instance, and then coupled to the more classification based techniques in order to resolve some of the ambiguities which occur as a result of the limited number of test points available