Decision making during production planning process under conditions of uncertainty needs a model in which parameters can be defined as uncertain ones. For improving such situation, a fuzzy production planning model is developed in this paper.
The proposed fuzzy model has tried to soften the rigid requirements in the traditional linear programming models making fuzzier the perception based on uncertainties. It is true that, in general, models with fuzzy constraints have got a better behavior than the model with fuzzy constraints and fuzzy coefficients but with the proposed model we can introduce to the model both types of uncertainties, fuzziness and lack of knowledge or epistemic uncertainty.
Since resolving the model by conventional scientific methods in applicable soft wares such as Lingo is time consuming, in next attempt we will research for an appropriate Meta heuristic approach to reduce the computer time -which is very important in executive environments- to solve the model.