There is a truck fleet to handle the distribution. Each truck starts its routes from the plant and fulfills all customers’ demand in the routes and then returns to the plant. Spilt delivery is not allowed which means that every customer’s demand must be satisfied by one truck on one stop. The capacity of each truck is fixed and if time allows, trucks can be assigned multiple 
routes within the time horizon. Our objective is to satisfy all customers’ demand on time and minimize the total 
transportation cost. This means determining the fleet size, each vehicle’s routes and plant’s production schedule.