Analysis of manufacturing flow lines with unreliable machines

We develop an analytical methodology for the analysis of a tandem manufacturing flow line with finite buffers and unreliable machines. The flow line is modelled using Open Queuing Networks. The methodology uses decomposition, isolation and expansion methodologies to calculate the throughput of the flow line. The methodology is tested rigorously. In order to cover a large experimental region, orthogonal arrays are used to design the experiments. The results of these experiments are compared with their corresponding simulation results. A t-test is carried out to investigate the differences between the simulation results and the results of the analytical methodology. The results show that the methodology developed is robust and remarkably accurate over a wide range of parameters.