In many domains, diagnosis requires several independent modules which produce sets of diagnoses based on examining the faulty device from different aspects of the behavior. For example, different modules might consider the mechanical, electrical, or thermal aspect of the device behavior. Individual modules can also employ different diagnostic strategies such as consistency-based or probabilistic diagnosis approaches depending on the requirement of their tasks. However, combining the results given by the different modules is a major difficulty in such an integrated diagnostic environment. The authors present a method for evaluating and synthesizing diagnostic hypotheses obtained from different modules. They discuss the resulting algorithm as it is applied to jet engine diagnosis, where the method provides a more focused and complete diagnosis than any single diagnostic system