Mathematical Problems in Engineering
Volume 2008 (2008), Article ID 364279, 21 pages
Research Article

Optimal Scheduling of Material Handling Devices in a PCB Production Line: Problem Formulation and a Polynomial Algorithm

Ada Che1 and Chengbin Chu2

1School of Management, Northwestern Polytechnical University, Xi'an 710072, China
2ISTIT, Université de Technologie de Troyes, BP 2060, 12 Rue Marie Curie, 10010 Troyes Cedex, France

Received 30 January 2006; Revised 22 October 2007; Accepted 15 March 2008

Academic Editor: Jerzy Warminski

Copyright © 2008 Ada Che and Chengbin Chu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Modern automated production lines usually use one or multiple computer-controlled robots or hoists for material handling between workstations. A typical application of such lines is an automated electroplating line for processing printed circuit boards (PCBs). In these systems, cyclic production policy is widely used due to large lot size and simplicity of implementation. This paper addresses cyclic scheduling of a multihoist electroplating line with constant processing times. The objective is to minimize the cycle time, or equivalently to maximize the production throughput, for a given number of hoists. We propose a mathematical model and a polynomial algorithm for this scheduling problem. Computational results on randomly generated instances are reported.