“…Certain targets (for example, the shortest driving route, the lowest distribution cost, the optimal logistics distribution and service level and the less number of distribution vehicles etc) have been reached through optimizing vehicle scheduling and under the premise of satisfying customer demands (Shorakaei, 2014). In research, some basic assumptions are usually made for constraint conditions, for example, accomplish distribution task with one distribution center and single type of vehicle; the distributed goods can be mixed; the location of each client and their distances to distribution center are already known; distribution center has enough goods for delivery and has enough transportation capacity (Panday and Bansal, 2015); each client is served by one vehicle and can only be served by one vehicle; the demand of each route can't exceed the maximum load of vehicle; all the vehicles depart from distribution center and go back to distribution center after accomplishing the task (Mcgehee, 2013;Mousavi et al, 2011;Skok et al, 2001) It may possibly need to consider about multiple distribution centers, multiple vehicles, time demand of customer service as well as the randomization of customer demand.…”