An Ambulance Routing Problem in Organ Transplant Supply Chain Considering Traffic Congestion

Organ transplantation is one of the most important pillars of health systems and has helped to treat many incurable diseases. Every day, 7 to 10 patients in Iran die because they do not have a transplant on time. Due to the criticality of the organ transplant chain for human health, the management and planning of this chain is of great importance. Timely transfer of organ and patient from one hospital to transplant hospital is very important considering the effect of seconds on the quality of the transferred organ and the success of the transplant. In this paper, a mathematical model for scheduling the pickup and delivery of transplanted organs and routing the ambulances carrying organs transplant and patients is presented. The problem is formulated in the form of a mixed integer nonlinear programming and then transformed into an equivalent linear mathematical model using exact operations research methods. The proposed model seeks to find the optimal schedule and sequence of pickup and delivery of organs and patients; under the operational constraints such as cold ischemia, urban traffic and limited fleet. The proposed model is optimally solved in CPLEX 12.8 software, and the computational results confirm the applicability of the proposed model.