Fatemeh Pourdehghan Golneshini - Department of Industrial Engineering, Mazandaran University of Science and Technology, Babol, Iran
Hamed Fazlollahtabar - Faculty of Industrial Engineering, Iran University of Science and Technology, Tehran, Iran

Nowadays, flow shop is the most common productionenvironment in industry. However, the need to increase orbalance the capacity in different production stages has ledto having more than one machine at some stages. The flowshops are usually categorized as hybrid flow shop,multi-processor flow shop, flexible flow shop or flow shopwith parallel machines. This article deals with the hybridflow shop scheduling problem with unrelated and eligiblemachines along with fuzzy processing time and fuzzy duedate. The objective is to minimize a linear combination oftotal completion time and maximum lateness. A mixedinteger mathematical model is presented for the problem. Anumerical example is worked out and various randomlygenerated test problems are used to investigate theefficiency of the proposed mathematical model.

Hybrid flow shop, mathematical model, fuzzy numbers, bi-objective programming