Estimating the performance of EMS location models via simulation

Official URL: http://192.168.1.20/record=b1378261 (Table of Contents)

In this thesis, we address the problem of evaluating deterministic EMS location models via simulation. For deterministic set covering location models, the performance of the model is typically determined by an objective function representing a certain type of coverage. After determining the location of EMS stations by deterministic models, we propose to conduct a simulation analysis to evaluate the performance by estimating the ''real'' coverage of the population. We compare 4 different deterministic models, Maximum Coverage Location Model (MCLM), Single Period Backup Double Covering Model (SPBDCM) which is a variant of MCLM, Maximum Service Restricted Set Covering Location Model (MSRSCLM) and finally Centralized Final Ratio Model (CFRM). By using optimization tools, we find the location of ambulances for each model by sıolving the mathematical models and then we simulate each setting for 2 different policies under the same parameters. The models' overall performance is firstly tested on Istanbul data and then followed up with extensive experimental study with different problem size, different layout and different arrival rates with two distinct policies. The tested policies include first come first serve with zero line capacity and lost call approach, and dispatching the closest idle station whether the call origin is served at the moment of the call or not. The study is then extended by a myopic heuristic, which basically tries to improve the performance of the system by relocating ambulances.