Estimation of Performance Measures of Emergency Services for Overload of Calls

The mathematical model of public-safety answering points (PSAP) functioning is constructed and analyzed. In the model the usage of interactive voice response (IVR) and the possibility of call repetition are taken into account. Algorithm of characteristics estimation based on truncation of used infinite space of states and solving the system of state equations is suggested. Relative error of characteristics calculation caused by truncation is found. Approximate algorithm of performance measures estimation is constructed. The usage of the model for elimination of negative effects of PSAP overload is considered.