Modelling and Solving Time Dependent Vehicle Routing Problem with Semi Soft Time Windows in Multi graphs

Today, with extension of industries and establishment of competitive market, owner of industry firms and service centers attend to operating cost reduction and consequently product or service final cost economization. Supply chain management (SCM) is a multi component tool used to reducing cost. One of its components is transportation management. The transportation has a major role in production and operating costs (Woensel et al., 2008). In the last 50 years, many of researchers have represented different mathematical methods to optimize transportations costs. The Vehicle Routing Problem (VRP) is one of the most significant said issues in transportation optimization. Many of researchers have attended to VRP and discussed different extensions of VRP in literature (Eksioglu et al., 2009) such as pickup and delivery vehicle routing problem (PDVRP), Vehicle Routing Problem whit Time Windows (VRPTW), Periodic Vehicle routing problem (PVRP) and so on. Totally, VRP problems are classified to two classes: static problems and dynamic problems. Many of articles with issue of VRP are static in which parameters such as times, demands and costs are put static in every time. This viewpoint to parameter of travel is not acceptable estimate for industries and service firms while these need more exact results. For this reason, Dynamic Vehicle Routing Problem (DVRP) is arisen to solve extant shortages in the static vehicle routing problems. In DVRPs are considered some of parameters as variant based on different situations.. ..