A Memetic Algorithm for Hybrid Flowshops with Flexible MachineAvailability Constraints

Subject Areas : Design of Experiment

Fariborz Jolai ¹ ( Department of industrial engineering, faculty of engineering, University of Tehran, Tehran, Iran )
mostafa zandieh ² ( Department of industrial management, management and accounting faculty, Shahid Beheshti University, Tehran, Iran )
Bahman Naderi ³ ( Department of indusrial engineering, Amirkabir University of Technology, Tehran, Iran )

Received: 2008-10-05 Accepted : 2009-04-09 Published : 2010-02-07

Keywords: Scheduling, Hybrid flowshops, sequence dependent setup times, machine availibility constraints, memetic algorithm,

Abstract :

This paper considers the problem of scheduling hybrid flowshops with machine availability constraints (MAC) to minimize makespan. The paper deals with a specific case of MAC caused by preventive maintenance (PM) operations. Contrary to previous papers considering fixed or/and conservative policies, we explore a case in which PM activities might be postponed or expedited while necessary. Regarding this flexibility in PM activities, we expect to obtain more efficient schedule. A simple technique is employed to schedule production jobs along with the flexible MACs caused by PM. To solve the problem, we present a high performing metaheuristic based on memetic algorithm incorporating some advanced features. To evaluate the proposed algorithm, the paper compares the proposed algorithm with several wellknown algorithms taken from the literature. Finally, we conclude that the proposed algorithm outperforms other algorithms.