Closed analytical formulae for evaluating flexible manufacturing system performance measures

SUMMARY Using the Z-transform method, closed-form analytical expressions for evaluating the performance of flexible manufacturing systems (FMS) are derived. The formulae are based on the operational analysis framework and allow the dependence of the performance measures on the main operational parameters to be clarified. Balanced, and nearly or completely unbalanced systems, are considered. In more complex cases, to improve the efficiency of computation, an algorithm is introduced, which decomposes the system into balanced and unbalanced parts, and allows the formulae already derived for these simple cases to be utilized. The intermediate results are expressed in the form of finite discrete sequences. From the convolution of these sequences, the behaviour of the whole system is obtained.