An Improving Vrp Model With Multiple-Depots, Multiple- Trips, Heterogeneous Fleets, Split Delivery For Municipal Waste Collection: A Case Study In Ho Chi Minh City

Abstract

Waste management has been considered as a major concern of many countries around the world for the decades. The global population has increased causing more complex waste management. Logistics is one of main activities of the waste management system which relates to the waste collection and manages the waste collection system in the gathering points and the transfer points. The cost of collecting and delivering waste accounts for the main part of the total cost of waste management, so improving the waste collection system takes a vital role to solve and reduce the problems of urban management. The previous research papers which study the VRP model with one transfer site, gathering sites and heterogeneous fleets are already applied. They almost concentratedly study the VRP model for the waste collection in the normal days (with stable waste quantities) but not in the special holidays such as Tet holidays with the considerable waste increment. The study in this paper concentrates on the utilization for the waste collection at the gathering sites when the waste quantities suddenly increase. The VRP model in this study is proposed to solve the problems with multiple transfer sites, multiple gather sites, multiple types of serving fleets. The multiple depots and multiple trips in the proposed VRP model are suitable for the practical requirements. The model also shows the flexibility of waste collection when multiple fleets or collecting trips with the split delivery are used at the gathering sites to collect all the waste quantities. The aim of the model is to optimize the cost of waste collection, which offers the utilization of the collecting routes for the fleets with the available resources. Besides, this research also proposes the solution approaches for the VRP model using CPLEX for the small datasets and Randomized K Nearest Neighbors and 2 Opt exchange and replacement for the large datasets. The VRP model in this research is applied to solve the waste collection problems at the provinces in Ho Chi Minh city.