Time window assignment vehicle routing problem with vehicle restrictions, time dependency and heterogeneous vehicles

• Main Authors: Lee, Lance Lindle O., Bacierto, Martin France J., Ng, Warren Justin L.
• Format: text
• Language: English
• Published: Animo Repository 2017
• Subjects: Vehicle routing problem; Operations Research, Systems Engineering and Industrial Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/18642
• Institution: De La Salle University

In a distribution network, it is a usual practice where it is the customers that quote the time windows to the suppliers. This type of vehicle routing problem has been heavily studied in the past years. However, there are some instances wherein it is the suppliers that quote the customers the time windows by which they can be serviced in a particular period. This variant of vehicle routing problem, known as time window-assignment problem vehicle routing problem (TWA VRP), has been studied recently. In this study, the use of heterogeneous vehicles, vehicle restrictions as well as time dependency were incorporated in TWA VRP. In the model, the objective function minimizes the total cost, and the major constraints consists of the routing, demand, time interval, time window, vehicle restrictions, leave time, and operating hours. The model was run through the GAMS software using a mixed integer programming approach. Eight (8) scenarios were tested in order to assess its impact on the routing and selection of vehicles to be dispatched. Based from the tests done, the length of vehicle restriction, the length of peak hours as well as the variation of the capacities of vehicles in the system have a significant impact on the routing of the vehicles. Aside from the capacities of the vehicles, the variation in the fleet mix as well as the variation of travel times were identified as drivers on what type of vehicles would be used in the system. Contrastingly, varying the width of the time windows for each customer have a negligible effect on the routing of the vehicles. Meanwhile, it was also found out from the test that incorporating time dependency on TWA VRP would significantly improve the performance of the system, in that, the number of vehicles to be dispatched is minimized.