Department of MIS and Decision Sciences, University of Dayton, Ohio, USA

Correspondence: Jay B. Ghosh, Department of MIS and Design Sciences, 300 College Park, Dayton, Ohio 45469-2130, USA

Abstract

In a recent paper, Cheng considers the multiple-machine extension to a due-date assignment and scheduling problem. He implicitly assumes zero start times for all schedules (which does not ensure optimality), and overlooks the critical V-shape property for an optimal schedule (which leads him to over-estimate the effort needed to solve the problem). In this note, we correct these flaws, and also discuss the complexity of the problem and its special cases.