Performance evaluation of unbalanced flow lines with general distributed processing times, failures and imperfect production

In this paper an analytical approximation for the performance of non-homogeneous asynchronous Flow Production Systems (FPSs) with finite buffers is presented. Generally distributed stochastic processing times as well as breakdowns and imperfect production are considered. The procedure explicitly accounts for simultaneous blocking and starving. The approximation is based on the decomposition of an M-station-line into M – 1 two-station-lines which are analyzed with the help of a GI/G/1/Nmax queueing model. Numerical comparisons with exact and simulation results for hypothetical as well as for real-life flow-lines indicate that the procedure provides accurate results.