We have developed two simulation models to conduct experiments on process flexibility, following the frameworks provided by Jordan and Graves (1995) paper. Our models deal with process, which have multiple products and multiple production facilities. By default each product can be produced in one of the facilities. And, flexibility can be added to system to make it possible for products to be produced in two or more facilities. These models allow researchers to experiment on impacts of change in values of product demand, variation in product demand, plant capacity and number of plants (or models) and overall flexibility on customer service and plant utilization.