Optimization of the assignment of circuit cards to assembly lines in electronics assembly

Process planning is an important and integral function for ensuring efficient operations in printed circuit card assembly systems. This paper presents a new approach for solving the circuit card to assembly line assignment problem to minimize assembly time. This problem occurs frequently in process planning for electronic assembly systems and involves considering other interelated process planning problems. The line assignment problem is formulated as a large-scale mixed-integer programming problem and then solved using problem decomposition along with the branch-and-bound algorithm. Techniques for improving the solution time are discussed, and the solution approach is demonstrated using industry representative data sets from Lucent Technologies. For the data sets considered, the solution approach provides solutions within 3% of optimal in approximately 6 min of computation time on a Sun UltraSparc 2 Workstation. The solution approach developed for addressing the line assignment problem can serve as a useful decision-support tool by offering significant opportunities to improve the productivity and throughput of the assembly lines with improved process plans. The approach also allows planning engineers to respond faster to changes in production requirements. This research will be of interest to researchers in printed circuit card assembly systems and to practitioners in both original equipment manufacturing and contract assembly firms.