Companies are desperately seeking a competitive advantage in today's fast-paced business world to outperform their rivals. Competition with the rate of rapid change in technology has made the issue of new product development in a competitive market important. One of the factors that effectively play a role in the new product development process, especially when competition, flexibility and product diversity are important, is the employment of work teams. Considering the importance of the subject, this study aims to present a new model of team assignment for new product development with a focus on improving the level of productivity. In this research, mathematical modeling logic has been used. Furthermore, the research model is a Multi-Objective Integer Linear Programming (MOILP) model and because discrete variables exist, the solution space is not continuous and convex but discrete and thus non-convex. Thus, the problem is NP-hard in terms of complexity. In the end, according to various factors for the assignment of human resources in new product development processes, a multi-objective mathematical model was designed to reduce costs, control wage rates, reduce work process time, and maximize productivity in the production system.