Optimization issues in automated production of printed circuit boards: Operations sequencing and feeder configuration problems

Automatic electronic component insertion machines are integral parts of Computer Integrated Manufacturing Systems in electronics industry. During the automated manufacturing of a printed circuit board (PCB), these machines insert electronic components, which are supplied from a set of sequential feeders, into predefined locations on the PCB. The sequencing of the insertion operation and the assignment of the component types to feeders directly influence production rate and overall system productivity. In this research, a heuristic procedure is defined and implemented, where these two interrelated problems are taken up iteratively, first one leading to a four dimensional asymmetric, non-Eucledian traveling salesman problem and the second one leading to a quadratic assignment problem. Through this approach, near optimal, but very practical and effective insertion sequences and feeder assignments can be generated for electronic components insertion machines. Result obtained for a series of random test problems are quite encouraging and will be presented, along with some important insights they have led to, about the developed solution procedure. An implementation to a real case, in a TV set production facility, will also be presented and, with this context, issues related to the validity of some critical model assumptions will be discussed.