BATCHING TO MINIMIZE WEIGHTED MEAN FLOW TIME ON A SINGLE-MACHINE WITHBATCH SIZE RESTRICTIONS

This paper considers a single machine job batching problem with multip le job types involved where each given type of job is allowed to split into several batches whose individual sizes are varied in integral nu mber and restricted between lower and upper bounds. Major and minor se tup times are also involved in batch sequencing. The objective is to f ind the optimal job batching and sequencing for minimizing weighted me an flow time which is measured in the ''batch-flow'' concept. In the a nalysis, a feasibility condition is derived to take care of the batch size restrictions, and some solution properties are characterized. The se are used to exploit a dynamic programming algorithm, and also to su ggest an effective heuristic algorithm. (C) 1997 Elsevier Science Ltd.