Production Scheduling in Knitted Fabric Dyeing and Finishing: A Case Approach

Abstract

The dyeing and finishing processes represent one of the most complicated scheduling problems existing in real production. The problem combines two difficult but challenging scheduling aspects together: a flexible job shop with sequence dependent setups. The process consists of multiple operations, which can have either single or parallel machines. Chemical and fabric pile contamination cause the sequence dependent setups. According to the business strategy of the case factory, the scheduling problem is categorized as two cases, no job priority and two-job priority classification (high and low). The scheduling objective is to minimize maximum lateness, Lmax. The fundamental structure used for solving the dyeing and finishing scheduling problem is the Virtual Factory plus family scheduling. The Virtual Factory is a simulation based job shop scheduling system developed at North Carolina State University. The scheduling heuristic used in the Virtual Factory is developed based on family scheduling. Jobs are grouped into families and then families are scheduled. The schedule is accomplished by switching the positions and splitting the family members. This dissertation intends to solve the real problem. Scheduling problems are generated using real problem characteristics. The experimentation indicates that with the advantages of fast computation time and heuristics modified easily, the best approach is to apply several versions of a heuristic to get the best possible solution.

Description

Keywords

scheduling, dyeing and finishing, sequence dependent setup

Citation

Degree

PhD

Discipline

Industrial Engineering

Collections