On minimizing average weighted completion time: A PTAS for the job shop problem with release dates

Abstract

We consider the non-preemptive job shop scheduling problem with release dates and the average weighted completion time objective. We propose here a polynomial-time approximation scheme (PTAS) for the case when the number of machines is constant and each job consists of at most a constant number of operations. This substantially improves on previous results [4], adds to a number of techniques [1,2,6,10,22], and gives some answers to the questions mentioned in [20,23]. © Springer-Verlag Berlin Heidelberg 2003.