CORMSIS seminar by Dimitris Paraskevopoulos Event

Optimisation Frameworks for Solid Waste Management: Network Design and Vehicle Routing

This paper presents optimisation frameworks for addressing solid waste management problems. The latter include both the distribution and allocation of waste containers on street segments of an urban environment, as well as the routing of waste collection vehicles. Initially, the waste containers network design problem is presented. Two types of waste streams are considered; common residential and recyclable waste streams, while different types of waste containers are used for each stream, respectively. Rigorous mathematical models are proposed for the location problem of both types of waste containers with an objective to maximize service convenience of waste producers subject to a set of network and service level constraints. The goal is to find the optimal distribution and allocation of waste containers to street segments such that the residual capacity of the waste containers in close proximity to the waste producers is maximized. Next, focus is given on the waste collection problems. Given the locations of the waste containers a set of heterogeneous fleet of vehicle is incorporated to collect waste on a daily basis. Different service frequencies for particular neighborhoods and streets, work shifts, accessibility restrictions and capacity constraints are considered. The goal is to minimize the number of routes, the total travel time and distance, and balancing workload among the waste collection vehicles. A clustering first-route second solution approach, that utilizes an efficient tabu search heuristic, is developed to address the related waste collection problem. Computational experiments on real-world instances with thousands of waste containers and hundreds of collection vehicles indicate the effectiveness of the proposed optimisation frameworks.