A particle swarm optimization for the vehicle routing problem with simultaneous pickup and delivery

The vehicle routing problem with simultaneous pickup and delivery is the variation of the vehicle routing problem that arises when a vehicle starts and ends its route at the depot and performs both the collection and delivery of goods when visits a customer. In this paper, we solve the problem using the Particle Swarm Optimization (PSO) and reproduce the results obtained by Ai and Kachitvichyanukul (2009). Additionally, we propose incorporating the single move (SM) and customer exchange (CE) heuristics in the algorithm to test if it can improve the solution quality. We compare the performance of the PSO, PSO with SM, PSO with CE and PSO with SM and CE. We find that the PSO with SM and CE gives the best and more robust solution at the cost of increased computational time