Completion times in serial mixed-storage multiproduct processes with transfer and set-up times

Abstract

The determination of completion times constitutes an important step in any algorithm for short-term production scheduling. In this paper, serial multiproduct batch/semicontinuous plants with a mix of interstage storage policies, nonzero transfer times and sequence-dependent set-up times are considered. A set of recurrence relations is presented for calculating the completion times for a given sequence of product batches on all processing units. The relations comprise an optimal, polynomially bounded, single-pass procedure which can be incorporated within any appropriate scheduling algorithm. Simplified expressions for several special cases of interest are deduced from the general results. Finally, important results concerning optimal production sequences for the limiting 2-unit configuration with infinite storage are derived.