An interval type-2 fuzzy model for Vehicle Routing Problems in supply chains

In Vehicle Routing Problems (VRPs) one tries to find the best route which begins and terminates at a unique center for a group of vehicles to service a number of customers. This paper presents a VRP in which parameters and continuous decision variables are assumed to be interval type-2 fuzzy sets. Since VRPs are NP-hard, the genetic algorithm (GA) is applied to solve the problem. Computational results are compared with type-1 fuzzy model. They show the efficiency of the proposed model and GA.