javad ahmadi moghadam

In this research, a model with three objective functions is presented to solve the problem of time, cost and quality trade-off in project planning. What distinguishes this model is that, in addition to considering different executive methods for each activity, rework activity is defined for some activities in order to prevent a decrease in quality. Other features of this model include covering various costs including incentive cost and tardiness cost. Because of the NP-Hardness of such large-scale problems, genetic algorithm is used to solve the proposed model.The results obtained from solving a real problem in screen filter production indicate that considering different executive methods for activities as well as different costs and defining rework activity can lead to better results towards the final goal by presenting a comprehensive model.If more accurate and detailed information is used for time, cost and quality in the model, it can achieve more rational results, similar to those of the real world more confidently. Under such conditions the least time and cost and most quality are achieved for successful implementation of project.