Missing Values and the Consistency Problem Concerning AHP Data

For AHP (Analytic Hierarchy Process) applications a paired comparison data matrix with special structure is needed. The limited ability of human respondents to provide paired comparison data that fulfil a consistency constraint and absent knowledge to judge all pairs of items under consideration can often result in data for which a best approximating complete AHP matrix has still to be found. We compare existing methodologies for the problem and describe an own approach to handle this situation. An illustrative example is used to explain our findings.