Performance Metrics Calculation for Assembly Systems with Exponential Reliability Machines

Assembly systems are commonly seen in production practice, where multiple components are joined in a manufacturing process to make a final product. In this paper, a decomposition/aggregation-based method is presented to evaluate the performance metrics of assembly systems with machines following the exponential reliability model (either synchronous or asynchronous). In particular, we consider the assembly system with multiple merge operations, each connected to a single external component line. The idea of the proposed method is to decompose the assembly system into a set of virtual serial lines based on the overlapping decomposition technique, evaluate of the starvation and blockage of the merge operations, and recursively update of the virtual machines’ parameters in the thus-obtained serial lines. Then, the performance metrics of the original assembly system can be approximated based on the corresponding machines and buffers in the virtual serial lines. Numerical experiments are carried out to justify the convergence and computational efficiency of the method, as well as to evaluate the approximation accuracy of the proposed algorithm.