Abstract:Various modeling techniques based on possibility distribution function has been applied successfully in a wide range of issues related to production planning. However, the possibility distribution function derived from the records recorded in the organization are not always available or changes in production environment may cause a variety of changes and volatilities in model and make it unreliable; changes such as: market demand, changes in types of production costs, capacity, resources, and administrative constraints. In this study fuzzy sets theory has been combined with material requirements planning (MRP). It is noteworthy that material requirements planning (MRP) is one of the most commonly used subdivision of production planning that combining it with fuzzy theory can be applied to develop decision making systems and make them more efficient. In addition, the uncertainties of industrial environments can be exerted properly into the production decision-making.