An overview of the analytic hierarchy process and its applications

The Analytic Hierarchy Process (AHP) is a theory of measurement for dealing with quantifiable a n d / o r intangible criteria that has found rich applications in decision theory, conflict resolution and in models of the brain. It is based on the principle that, to make decisions, experience and knowledge of people is at least as valuable as the data they use. Decision applications of the AHP are carried out in two phases: hierarchic design and evaluation. The design of hierarchies requires experience and knowledge of the problem area. Two decision makers would normally structure two different hierarchies of the same problem. Thus a hierarchy is not unique. On the other hand, even when two people design the same hierarchy, their preferences may yield different courses of action. However, a group of people can work together to reach consensus on both the hierarchy (design) and on the judgments and their synthesis (evaluation). The evaluation phase is based on the concept of paired comparisons. The elements in a level of the hierarchy are compared in relative terms as to their importance or contribution to a given criterion that occupies the level immediately above the elements being compared. This process of comparison yields a relative scale of measurement of the priorities or weights of the elements. That is, the scale measures the relative standing of the elements with respect to a criterion independently of any other criterion or element that may be considered for comparison. These relative weights sum to unity. The comparisons are performed for