Analytic hierarchy process
AHP is a decision-making method that decomposes a complex MCDM problem into a
hierarchy (Saaty, 1980). It is also a measurement theory that prioritizes the hierarchy and
consistency of the judgmental data provided by the decision-making group. AHP
incorporates the evaluations of all decision makers into a final decision, without having
to elicit their utility functions on subjective and objective criteria by using pairwise
comparisons of the alternatives (Saaty, 1990). The calculation procedure is presented in
detail as follows:
1. Establish the hierarchy structure. A complex issue can be addressed by
decomposing the hierarchical structure. Given the inability of humans to simultaneously
compare seven categories, it is assumed that each element of the hierarchy will not
exceed seven elements, ensuring reliable comparison and consistency (Saaty, 1980). The
first hierarchy of the structure refers to the targeted goal, the middle hierarchies
comprise the appraisal factors or criteria and the final hierarchy consists of choice
projects or replacement alternatives.