Scheduling of drilling operations in printed circuit board factory

The drilling operation of the printed circuit board is very critical and usually is a bottleneck operation of the whole manufacturing processes. Therefore the scheduling problem of the drilling operation is very challenging and difficult because usually there are more than 50 machines on the shop floor waiting to be sequenced. The shop orders are all different based on their application purpose such as in PC industries, or telecommunication applications, i.e. the cellular phones. These orders have to be sequenced on the drilling machines and the objective of this research is to schedule these drilling operations in a near optimal manner under various constraints. Due to the complexity of this problem, a heuristic approach, i.e. the tabu search, is applied to provide a practical solution within a timely manner. Experimental results are examined to test the efficiency and effectiveness of the tabu search. When compared with the manual approach provided by the shop floor scheduler, the tabu search outperforms significantly.