An efficient solution to cyclic scheduling of a no-wait reentrant serial-parallel PCB production line

The manufacturing of printed circuit boards (PCB) involves multi-stage production lines where material handling is performed by a computer-controlled hoist. This paper addresses cyclic scheduling of a no-wait reentrant serial-parallel production line in PCB manufacturing. A reentrant serial-parallel production line is a production system with reentrant and parallel stations. A reentrant station is a processing station visited by parts more than once, and parallel stations are a group of stations performing the same processing at some bottleneck production stage. We first formulate our scheduling problem using the notion of prohibited intervals, and then perform a formal analysis on the developed mathematical model. Based on this analysis, we propose a polynomial algorithm for the considered problem. An illustrative example is given to verify the proposed algorithm.