Document Type : Research Paper



In this paper we develop the concept of boring caused by doing the same jobs to two types of boring, negative or undesirable and positive or desirable, which are felt by operators because of doing similar jobs and not only due to doing the same ones. Based on this new concept, the flexible model has been proposed by which jobs will be scheduled to minimize the total cost of assignment including the cost of doing the jobs by operators and the boring cost so that job scheduled with respect to their similarities in the smallest time period as well as dissimilarities in the biggest given time period. For the reason that the proposed job rotation scheduling model has a multi-­period assignment structure and formulated as an integer non-linear model, it is recognized as a combinatorial optimization problem. So applying the metaheuristic algorithms to overcome the complexity of such a problem is required. We use the genetic and imperialist competitive algorithms to do that and verify their efficiency in comparison to that of Lingo software which solves the small integer nonlinear problems. It is also shown that the quality of imperialist competitive algorithm solutions is better than those of genetic algorithm for the proposed model.