A theory of exposure: Measuring technology system end user vulnerabilities
People are reliant on technology systems for their survival and everyday convenience. From access to clean drinking water, to electricity for cooking, to fuel for driving vehicles to and from work. When a technology system that people rely on is inoperable or inaccessible, end-user vulnerabilities can increase acutely and substantially. While end-users are quite resourceful, a few days without water or electricity or fuel, can quickly turn into a humanitarian or security crisis, especially in densely populated areas. This paper's contribution is a measure to study technology systems and the extent of their contribution to end-user vulnerability. A theory of exposure is presented with a corresponding measure of how to determine exposure of any given technology system, agnostic of geography location or socio-economic circumstances. It is argued, that if the exposure of any given technology system can be reduced, that end-user vulnerabilities are also reduced, providing some control over extreme or unintended events. Researchers and practitioners can use these outcomes on existing technology systems toward optimization, or on new technology systems being introduced into a cyberphysical environment. The accuracy, precision and scaling of the proposed exposure measure are also examined in this paper.