Mixed integer linear programming models for scheduling the LED planting operation on PCBs

This paper deals with a scheduling problem arising in printed circuit board (PCB) assembly. In this problem, LED components are to be assembled in batches to specified positions on PCBs by a high speed assembly machine and the position sequence for component assembly needs to be optimized. Three different mixed integer linear programming (MILP) models are proposed for the problem. Problem instances based on real data are generated and used to test and compare the models. The models are solved using a commercial software package. The results show that the model with the minimum number of constraints can find the optimal solution in the shortest time.