Optimal reset number of a microprocessor system with network processing

As computer network technology has remarkably developed, microcomputers which form data terminal equipment (DTE) in a communication network have been used in many practical fields and the demand for improvement of their reliabilities has greatly increased. In fact, a microprocessor (μP) which is one of vital devices of a communication network often fails through some faults due to noise and changes in the environment and programming bugs. Therefore, it is necessary to take preventive measures for occurrences of such errors. This paper considers the maintenance problem for improving the reliability of a μP system with network processing. After the system has made a stand-alone processing, it executes successively communication procedures of a network processing. When either μP failures or application software errors in the system have occurred, a μP is reset to the beginning of its initial state and restarts again. The reliability quantities such as the mean time to the success of a network processing and the expected reset number, using the theory of Markov renewal processes, are derived. An optimal reset number, which minimizes the expected cost until a network processing is successful, is analytically discussed. A numerical example is finally given.