Vehicle Routing Problem with Regard to Simultaneous Pickup and Delivery, Time Windows and Workers Assignment on the basis of their abilities and Availability

Abstract : The vehicle routing with simultaneous pickup and delivery, which considers simultaneous distribution and collection of goods to/from customers, is an extension of the capacitated vehicle routing problem (CVRP). In such matters, all the vehicles start moving from a central depot and stop working in the same center. Demands of each node should be served exactly once and only by one vehicle. All the customers' requirements must be met. In simultaneous pickup and delivery (VRPSPD), vehicles can perform pickup and delivery processes in each node simultaneously and the whole loading products should be returned to the central depot. In this paper, VRPSPD is considered with regard to hard and soft time windows. Some workers are applied to perform the pickup and delivery processes that they should be assigned to the vehicles depending on their abilities and also their availability. By considering pickup and delivery processes with time windows and allocation of workers, wider range of current issues in the real world will be included. We entitle this novel problem VRPSPD-TW-WA and propose a mathematical model to handle with it. Finally, the precision performance of the proposed model is assessed by solving some test problems via GAMS 24 software.