Analysis of production lines with general service times and finite buffers: A two-node decomposition approach

A production line consisting of work stations in series with general process completion times and with finite intermediate buffer storages is considered. Work stations may get blocked due to the limited space in the buffer storages. An approximation method is developed to compute the steady-state distribution of the number of jobs in each work station, from which the performance measures for the production line can be computed. The method decomposes the production line into subsystems of two nodes with general processing times and with a finite buffer storage in between. The first node represents the behavior of the upstream part of the line while the second node represents the behavior of the downstream part of the line. These two-node subsystems are analyzed in isolation within an iterative scheme which relates them to each other. The consistency among the two-node subsystems is achieved by making their throughputs the same. The iterative scheme always converges. The method is general enough to cover a wide range of production lines. It is computationally highly efficient and it has an acceptable error level.