Balancing printed circuit board assembly line systems

This paper considers the placement of components onto printed circuit board s (PCBs) using surface mount technology. Multiple automatic placement machi nes, a variety of PCB types and a large volume for each PCB type characteri ze the environment studied. The problem addressed is that of allocating and arranging the components on several placement machines, organized into one or several assembly lines, while considering a different assembly time if components are located at different feeder locations. The one assembly line problem is equivalent to balancing a multi-model assembly line where model s are assembled in small batches without component rearrangement between mo del changes. The objective is to minimize the weighted sum of each assembly PCB cycle time, which is defined as the maximum time a PCB has to spend on each machine. We solve this problem with Lagrangian relaxation techniques. Industrial case study results are presented. We also compare the global pe rformance of five placement machines if they are organized as a single asse mbly line or broken down into two or more assembly lines.