This paper aims to put a new approach in the picture to the payment scheduling problem, which looks for a schedule that maximizes the benefit of all parties in a project. In a project, both sponsor and contractor seek to have a good payment strategy on their own. The timing of payments and the completion times of activities in projects are determined simultaneously in order to achieve an equitable schedule among the sponsor and the development team. In previous research, we developed a Unified Game-Based Model for conflicts in project management. In this paper, we applied this model to this problem, implemented in an open sourced evolutionary computation library named MOEA framework. The use of a Unified Game-Based Model enables us to figure out a suitable schedule for the problem, and in the tool, we conducted an experimental test of the model by the used of several multi-objective optimization algorithms. The experimental results demonstrated that the presented approach is effective and promising so that both parties could use this model to choose the proper tactics for each of them in scheduling payment.