CLASP: a computerised aid to cost effective perimeter security

The problem of providing cost-effective perimeter security for prisons was addressed by the development of a mathematical model to evaluate a set of performance measures. This model was designed to evaluate perimeter security, starting from the assumption that an escaped person has reached the perimeter, and calculating the chances of preventing a subsequent escape. The author describes the evolution from the initial formulation of a model, to an operational computer software package the current version of which is known as CLASP (computerized layout analysis for secure perimeters). Conclusions about the future prospects of using a computer package for perimeter security decision making are drawn from this experience