Component fixture positioning/sequencing for printed circuit board assembly with concurrent operations

This paper considers the problem of positioning component fixtures on the carriers of computer, numerically controlled dual delivery machines used for populating printed circuit boards with surface mounted technology. This reel positioning problem (RPP) is one of a series of optimization problems that are critical for improving system productivity and realizing the full potential of concurrent operations. We formulate the RPP as a mathematical program and establish its complexity. Since the problem is NP-complete we focus on the development of heuristics. Our solution procedure was prompted by engineering considerations that included concerns for minimizing the changes in the carrier direction and total movement. We also present encouraging results with test problems. The method has been implenented and achieved 7 to 8% reductions in cycle time.