Operational planning of electronic assembly systems in the presence of state dependent setup and processing times

Abstract

Optimization of the machine and line level issues in an electronic assembly system (EAS) is imperative for the efficient use of resources in the system. This research considers the joint optimization of machine and line level issues in an EAS. Joint optimization differs from traditional sequential optimization in that sequential optimization first resolves feeder arrangement and placement sequencing issues to improve the processing time for each individual product. This is followed by the resolution of product-machine allocation and sequencing and scheduling issues to improve system performance by reducing setup times. However, in an EAS, processing and setup times are highly interdependent and, consequently, a sequential optimization approach may not give good results. In this research, the joint optimization problem is introduced and a framework for modeling the joint optimization problem through the introduction of the concept of state dependent setup and processing times is provided. Two solution procedures are then proposed for the joint optimization problem. This is followed by an experimental comparison of sequential and joint optimization procedures, considering multiple, identical placement machines, operating in parallel. This comparison helps analyze the potential benefits that could be obtained by using joint optimization.