An improved EMS simulation-optimization model with Poisson mixture distribution
A Discrete Event System (DES) simulation and optimization model is proposed for the ambulance allocation problem in an Emergency Medical Service (EMS) system. The accuracy of the proposed model is enhanced by estimation of input parameters using Poisson mixture distribution and the Expectation Maximization Algorithm. The results are proven by Mann Whitney and Kolmogorov Smirnov tests. The DES model is run by OptQuest program embedded in Arena software. The response times of the cases within the urban and rural regions are improved by 40% and 45%, respectively, and the stations success rates in urban and rural areas are raised to 95% and 96%, respectively. Our results indicate that the number of ambulances and their allocations to stations in the real system needs to be reorganized to achieve the required EMS system performance standards.