Improving locational decision making: a heuristic that optimizes access and coverage

Siting decisions can influence access, logistics, supply chains and transportation and other qualities, making them critical to the success of a service system. Often access to resources or opportunities is the primary concern, but other performance characteristics can be equally important. This paper considers access combined with service coverage in site selection as a bi-objective spatial optimization model. Specifically, the access objective aims to minimize demand proximity to its closest sited facility and the coverage objective seeks to maximize demand within a service distance standard. Solution of the problem is challenging due to the nature of facility location, where siting may occur anywhere in continuous space. Further complicating matters is the need to identify tradeoffs, or nondominated solutions, as the problem involves two objectives being simultaneously optimized. This research introduces a heuristic approach to solve a multi-facility, bi-objective location-allocation problem involving facility location in continuous space, where access and coverage are simultaneously considered. A unique case study is reported involving the strategic positioning of outfielders in baseball, where fielder access and coverage to batted balls are fundamentally important. The heuristic is found to perform exceptionally well, identifying the best range of solutions for this problem from which strategic placement of fielders can be planned.