vehicle routing with time windows and customer selection for perishable goods

delivering perishable products to customers as soon as possible and with the minimum cost has been always a challenge for producers and has been emphasized over recent years due to the global market becoming more competitive. in this paper a multi-objective mix integer non-linear programming model is proposed to maximize both profits of a distributer and the total freshness of the several products to be delivered to customers with respect to their demands and with consideration of different soft time windows for each customer, heterogeneous distribution fleet and customer selection option for the distributer. the proposed model is solved with th method. the two genetic algorithm and simulated annealing algorithm are used to solve large-sized problems. finally, their results are compared to each other when the optimization software becomes unable of solution representation.