Research on optimal method for fault maintenance strategy based on AND/OR graph searching

The excellent maintainability is the significant characteristic of the aero-engine, which ensures the maintenance high quality, high efficiency and low cost, but values of one attribution of aero-engine fault are more than one. In this paper, we consider a multi-valued test sequencing (MVTS) problem, in which a test may have an arbitrary number of possible outcomes denoting different behaviors. The multi-valued test sequencing problem can be solved through dynamic programming to find the optimal test sequence, but the time and space is large. In order to deal with this problem, we propose multivalued AO* algorithm, called MVAO*, based on multivalued heuristic evaluation function (MVHEF) in the AO*. With one aircraft gas turbine engine, we demonstrate that MVAO* is efficient and effective for optimizing test sequences problem with multiple test responses.