Here we introduce the Analytic Hierarchy Process as a method of measurement with ratio scales and illustrate it with two examples. We then give the axioms and some of the central theoretical underpinnings of the theory. Finally, we discuss some of the ideas relating to this process and its ramifications. In this paper we given special emphasis to departure from consistency and its measurement and to the use of absolute and relative measurement, providing examples and justification for rank preservation and reversal in relative measurement.