mohammad mahdavi mazdeh - Department of Industrial Engineering, International University of Science and Technology. Tehran, Iran
Farzad Zaerpour
Abalfazl zareei

This paper addresses the combined issues of maintenance and parallel machine scheduling in a deteriorating system. Unplanned breakdown can affect mahines and then machines may not be available all the times. On the other hand, each machine deteriorates at a random rate. This deterioration is considered in terms of cost which depends on production rate, machines operating characteristics and the kind of work done by each machine. Moreover, jobs’processing times are increasing function of their starting times and follow a simple linear deterioration in a deteriorating system. In this paper, we consider and develop a model for the parallel machine bi-criteria scheduling problem (PMBSP) with the aim of minimizing total weighted tardiness and minimizing machine deteriorating cost, simultaneously. The problem of minimizing total weighted tardiness in parallel machine is NP-hard in strong sense [24, 25], thus the combinatorial problem in which the objective function is minimizing the total weighted tardiness plus machine deteriorating cost is also NP-hard. Numerical example shows the efficiency of this model.

Scheduling and Sequencing, Parallel machines, Deteriorating system, Maintenance, Multiple objectives integer programming