Minimizing Customers' Waiting Time in Vehicle Routing Problem with Unit Demands

Abstract

This thesis aims to study a mathematical optimization model for minimizing customer waiting times in the context of the Unit Demand Vehicle Routing Problem. A Mixed Integer Linear Programming (MILP) formulation is developed to tackle the problem, focusing on customer-centric objectives rather than traditional cost minimization. The model is implemented using the commercial solver IBM ILOG CPLEX, which allows for solving medium-sized benchmark instances derived from the TSPLIB. The ob- tained results are then compared with those from existing literature to evaluate the effectiveness and performance of the proposed approach. This work highlights the importance of integrating service quality metrics such as latency into modern vehicle routing models. Keywords: Vehicle Routing Problem (VRP), Unit Demand, Customer Waiting Time, Mixed Integer Linear Programming (MILP), CPLEX, Exact Methods, Service Optimiza- tion, Latency Minimization, Combinatorial Optimization.