In a typical hierarchy, the top level reflects
the overall objective of the decision maker.
The elements aecting the decision are called
criteria, and they are represented at the intermediate levels. Criteria can be further divided
into subcriteria for additional refinement. The
criteria can be subjective or objective, depending on the means used in evaluating the contri-bution of the elements below them in the
hierarchy. Furthermore, criteria are mutually
exclusive and do not depend on the elements
below them in the hierarchy. The lowest level
comprises the decision options or alternatives.