A generalized-exponential decomposition method for the analysis of inhomogeneous assembly/disassembly systems with unreliable machines and finite buffers

This paper presents a new approximate analytical method for the performance evaluation of inhomogeneous assembly/disassembly (A/D) systems with machines subject to failures and finite buffers. Processing times of machines in these systems are deterministic but not identical. Times between failures and times to repair are both assumed to be exponentially distributed. The method developed in this paper provides a generalized approach for analyzing A/D systems. Unlike the previous work on this subject, generalized exponential distributions are adopted instead of exponential distributions to approximate the repair time distributions of the fictitious machines. As a result the proposed method can handle the situation where the orders of magnitude of machines’ reliability parameters (mean times between failures and mean times to repair) are not at the same level. A new algorithm is also developed to improve the convergence reliability and efficiency of the method. Extensive numerical experiments and simulation have been carried out to illustrate that the method proposed for A/D systems is quite accurate and efficient.