A production scheduling method in a knitted fabric dyeing and finishing factory

Abstract

This thesis concerns the development of a production scheduling system at a case 7 study, which is a knitted-fabric dyeing and finishing factory. There are many stages in the production process and each process has a number of machines. At present, schedules are planned with experience of schedulers with no formal procedure. There are many problems that arise from this practice, namely unbalanced workload among workstations and departments, high work-in-process, chaotic shop floor, high loss due to defects and long production lead-time. The scheduling system developed in this thesis uses heuristic methodology which is based on constraint-guided heuristic search, group scheduling and dispatching rule. A database is also developed to support the scheduling. Although the scheduling method developed here, being a heuristics , does not guarantee best results, it has been proven very satisfactory. The comparisons between the production performances from the developed method and existing method shows that the production lead-time and work in process are reduced significantly, machine utilization and quality of product are also improved. Reductions of raw material inventory, although not formally measured, are observed.