Sequencing, scheduling and tooling single-stage multifunctional machines in a small batch environment

Abstract

Single-Stage multifunctional Machining Systems (SSMSs) are an important integral part of automated, flexible manufacturing systems. However, the SSMS frequently becomes the bottleneck of the entire manufacturing system by virtue of protracted internal set-up requirements. A key aspect of achieving full SSMS utilization is the ability to reduce as much as possible these demands at the expense of increasing external set-up. As of today, fixturing devices have not received much attention in the modeling literature. Nevertheless, fixturing devices are in some cases a limited resource which, may affect the shop scheduling decisions and the shop performance and as such can not be omitted. This study presents a {0–1} programming model which takes the fixturing device's limitation in to consideration when determining the weekly sequence of jobs to be produced. The model tries to minimize the nonproductive machine time. Based on this model, a heuristic procedure is developed and tested using data of four production weeks obtained from a hi-tech company that produces medical imaging systems.