Review, extension and prediction in emergency service siting models

This is a review of a selected set of location papers and a research agenda. The location models reviewed fall into three categories: (1) basic deterministic covering models, (2) deterministic models which consider the value of additional covering servers, and (3) probabilistic models which allow randomness in server availability. Contributions in each of these categories are compared in a sequence which highlights the intellectual evolution of the models. Several new models are structured using the new formulation tools that are described. Several additional models whose development is predicted are described verbally.