Machine sequencing formulations typically assume that the characteristics of the job set to be processed are given. However, in many applications, jobs can be batched in different ways. Two types of minimum flow-time sequencing problems with lot sizing are formulated. The "item-flow" formulation...

Traditional scheduling models have emphasized sequencing of tasks at machines. At multiple-machine work-centers mean flow times are affected by the allocation of work to machines, as well as the batch-sizes used for processing. An efficient algorithm for computing the optimal solution for the...