Hybrid flowshop scheduling with family setup time and inconsistent family formation

Abstract

This research considers a hybrid flowshop scheduling problem where jobs are organised in families according to their machine settings and tools. The family setup time arises when a machine shifts from processing one job family to another. The problem is compounded by the challenges that the formation of job families is different in different stages and only a limited number of jobs can be processed within one setup. This type of problem is common in the production process of standard metal components. This paper aims to propose two approaches to solve this problem. One is a metaheuristic in the form of a genetic algorithm and the other is a heuristic. The proposed approaches are compared and contrasted against the two relevant metaheuristic and heuristic adapted from solving a generalised sequence-dependent setup flowshop problem. Comparative results indicate that the proposed genetic algorithm has better performance on minimising makespan and the heuristic is more effective on reducing family setup time.

Keywords:

• hybrid flowshop scheduling
• family setup time
• metaheuristic

Acknowledgements

We are most grateful to various companies who provided technical and financial support. The authors would like to acknowledge the financial support of HKSAR ITF (GHP/042/07LP), HKSAR RGC GRF, HKU Research Committee Projects, Guangdong Modern Information Service Fund 2009 (06120940B0260124), 2010 Guangdong Department of Science and Technology Funding (2010B050100023), National Natural Science Foundation of China (61074146), International Collaborative Project of Guangdong High Education Institution (gjhz1005) and The Fundamental Research Funds for the Central Universities (No. 2011ZM0079).