Performance analysis of assembly systems with unreliable machines and finite buffers

An unreliable assembly system is studied in which different types of components are processed by two separate work centers before merging to an assembly station with random breakdown. Blocking at the work centers and starvation at the assembly station may occur because of finite buffer sizes and uncertainties in job arriving times and processing/assembly times. We derive the system stability condition, and obtain formulas for the system state probabilities, blocking probabilities, starvation probability, stockout probability, system availability in the steady state. We also obtain the distributions of blocking times and first failure times, respectively. Through numerical examples, we elaborate on the monotonous properties of the performance measures, and draw the insights into the impacts of the system parameters on its various performance indices, which provide important guidance for design of assembly systems.