The AHP further utilises a quantitative approach
that employs pair-wise comparison to determine
the priority weights and the overall ranking of the
alternatives. In the hierarchy, the overall goal
(usually the selection of the best alternative) is
located at the highest level; elements with similar
features (usually evaluation criteria or sub-criteria)
are grouped at the same middle level and decision
variables (usually candidate alternatives) are situated
at the lowest level. Finally, in the AHP, the relative
weights of every component are calculated and, then,
aggregated and synthesised for the final measurement
relating to each of the decision alternatives