SUMMARY
Proper sequencing between activities has always been one of the major issues in project management. In some projects, especially new product development projects, an improvement in repetitions will cause rethink in the activities and possibly redo them. Therefore, time and cost of the project should be minimized by minimizing repetitive processes and feedback on activities. In this article, a network of activities is considered, which may require a duplication of the process due to the interdependence of information between them. It is assumed that one of the reasons for reworking some activities and backward can be due to the incompleteness of the information needed when doing some activities, while having complete information requires cost. In this paper, using the design structure matrix concept and interdependence between activities, a two-purpose model for determining the proper sequence of activities have been provided to minimize the length of feedback and reduce the cost of completing the information using matrix concept. To accurately solve this model, the combination Lexicographic and Augmented Epsilon Constraint is used to obtain the Pareto National Front, which shows an increase in the cost of reducing the degree of dependence between activities for reducing the feedback length between activities. From the Pareto front, the best answer was chosen in a way that, based on the economic justification of the project, the percentage of reduction in the feedback length would be higher than the percentage increase.