Analytical Methods for the Performance Evaluation and Improvement of Multiple Part-Type Manufacturing Systems

Abstract

This thesis investigates approximate analytical methods for the performance evaluation of manufacturing systems that produce multiple part-types. The systems consist of serial processing stations composed of unreliable machines decoupled by finite intermediate buffers.

A new decomposition-based method is developed for analysing systems where parts are stored in dedicated buffers. Systems with the following features commonly observed in real production lines are analysed: I) machine setups, II) bypass routings, III) stations comprising of multiple machines that are either dedicated or shared among part-types. The performance improvement of a system based on a real production line is also investigated.

Approximate methods are also proposed for analysing systems where part-types share common buffers. Several important characteristics including machine setups and hybrid manufacturing (both manual and automated processes) are accounted for in the analysis.

Comparison with simulation shows the good accuracy in performance estimation and greater computational efficiency of these methods.