Tandem manufacturing systems with machine vacations

This paper develops a methodology for the analysis of tandem manufacturing systems where a machine takes a vacation (i.e. becomes unavailable for some reason such as processing secondary jobs or being repaired) of random duration every time the corresponding station becomes empty. The system is modelled using a queueing network in which decomposition. isolation and expansion methodologies are used to calculate the throughput. The methodology was rigorously tested by designing experiments using orthogonal arrays to cover a large experimental region. The results are compared with benchmark results obtained through simulation. The differences between the two results are investigated using t-tests. The methodology developed proved to be robust and very accurate.