Designing supply chain network using vehicle’s routing approach and timeline and search of gravity force algorithm

One of the important characteristics in the supply chain is the transportation of materials and products between different regions. The distribution of raw materials on each level, like the joints of a chain, connects these levels. Therefore, distribution and transportation have an important role in the cost of products, because improving the vehicle’s route at distribution and transportation of materials and products in the supply chain will reduce the cost of products. In this article with a case study in one of the logistics supply chains of Iran, customer demand is considered and the model of vehicles routing problem is proposed according to the conditions of the company under study, which is a model of routing problems of open vehicles with a timeline. The objectives of this model are to achieve the lowest cost of distribution as well as the cost of quality degradation due to defects in the transportation system and also the optimal size of the distribution fleet to meet customers demand.

method of this research’s studies is library and regarding that these are case study, fields and observation methods are used. To identify the customers and their demands and also characteristics of investigated product and characteristics of vehicles assumed in the problem, reports are extracted from information system of logistic company. To achieve the objectives of this research multi-objective Gravitational Search Algorithm (MOGSA) has been used to solve open vehicles routing problems along timelines. Optimized navigation routing is done regarding the presented descriptions about gravity force. It means that optimization operation is done by multi-objective Gravitational Search Algorithm

The matter that any navigation to serve the customers should traverse which route depends on type of problem which is optimized by multi-objective Gravitational Search Algorithm and regarding the achieved beam front, for the optimized navigation base on algorithm a path will be traversed in which some of customers will be in route whom according to their demands and vehicle’s capacity can be.

To decrease the transportation costs, distribution companies’ requirements to exterior assignment of their products transportation is increasing. When the exterior assignment is done vehicles after loading of products and service, don’t need to return to the main depot and they can return to any of their desired routes after service. In the current study the product distributor company by exterior assignment of distribution operation to another company decreased the costs of vehicle maintenance and amortization into zero and as a result there’s no need to return the vehicle into the main depot.