A vehicle routing problem for biological sample transportation in healthcare: mathematical formulations and a metaheuristic approach (2104.09275v1)

Abstract: In this paper, a real-world transportation problem is addressed, concerning the collection and the transportation of biological sample tubes from sampling points to a main hospital. Blood and other biological samples are collected in different centers during morning hours. Then, the samples are transported to the main hospital, for their analysis, by a fleet of vehicles located in geographically distributed depots. Each sample has a limited lifetime and must arrive to the main hospital within that time. If a sample cannot arrive to the hospital within the lifetime, either is discarded or must be processed in dedicated facilities called Spoke Centers.Two Mixed Integer Linear Programming formulations and an Adaptive Large Neighborhood Search (ALNS) metaheuristic algorithm have been developed for the problem. Computational experiments on different sets of instances based on real-life data provided by the Local Healthcare Authority of Bologna, Italy, are presented. A comparison on small instances with the optimal solutions obtained by the formulations shows the effectiveness of the proposed ALNS algorithm. On real-life instances, different batching policies of the samples are evaluated. The results show that the ALNS algorithm is able to find solutions in which all the samples are delivered on time, while in the real case about the 40% [5] of the samples is delivered late.