2.5. Analytical Hierarchy Process

Analytic Hierarchy Process (AHP) is one of multi criteria decision making methods that was originally developed and first time presented in [27]. It is a method to derive ratio scales from paired comparisons. The AHP starts by decomposing a complex, multi-criteria problem into a hierarchy where each level consists of a few manageable elements (group criteria C_i) which are then decomposed into another set of elements (criteria C_ij). Later, these criteria (C_ij) are mutually compared in order to get the priority of each criterion in hierarchy. Finally, all alternatives are compared in relation to the set of criteria (C_ij) and in this way the comparison of alternatives (A_i) is obtained. The detail description of AHP flowchart is shown in Figure 1 [28].

Analytical Hierarchy Process methodology [28].

In order to get the final result and in order to get the gradation of influence for each criterion, first it is necessary to compare criteria mutually. The comparison of any two criteria C_i and C_j with respect to the goal is made using the questions of the type: of the two criteria C_i and C_j which is more important and how much. In reality, however, an individual cannot give estimates such that they would conform to perfect consistency. It means that the final result might be accepted when consistency ratio (CR) is <0.1, less than 10%. Otherwise, the problem has to be revised [29].