Hoist scheduling for an anodizing plant at an extrusion company

Abstract

The field of scheduling metal surface treatment plants is extensively studied in the literature and it is referred to by the name of Hoist Scheduling Problem (HSP). HSP is classified as a flow-shop scheduling problem, but differs because of the transportation constraints and the no-wait restriction. This research deals with a real anodizing plant in an extrusion company with multiple-hoist. The objective of this study is to minimize the makespan of a demand of selected days and to improve production of the plant. A heuristic algorithm was developed for scheduling the anodizing demand of the extrusion company. The algorithm was coded in Matlab (R2015b – editor) to simulate the production of certain days. The runs of the simulation were divided into three phases: validation phase; experimentation phase; and productivity enhancement phase. The results showed a reduction in the makespan with an approximated average of 18%. Furthermore, it revealed that the algorithm was able to utilize the time by an approximated average of 98% and to increase the number of jobs by an approximated average of 20%.

Keywords

• anodizing plant
• heuristic algorithm
• hoist scheduling problem
• makespan minimization