Criteria Constraints Criteria Weighting

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2.3. Spatial Multi Criteria Decision Analysis

Mostly decision is made under many criterions criteria, rarely depend on single criterion. The term multi criteria decision making analysis is used to explain the decision methodology which involve incommensurate criteria. Based on Worral 1991 in Malczewski 1999, 80 of data used by managers and decision makers is related geographically. Furthermore, spatial decision is multi criteria in nature. Consequently, there is a need for utilizing spatial multi criteria decision analysis that dealt with geographical data, which previously used for aspatial problem. Malczewski 1999 thought spatial multicriteria decision analysis as a process that combines and transforms geographical data into resultant decision through decision rules multi criteria decision procedures. At least three components should be considered to utilize multi criteria decision making, i.e.: decision criteria, criteria’s weight, and decision proceduresrules. The following subsection describes these components.

2.3.1. Criteria

Criteria are also referred as attributes. In spatially based decision making, the attribute is represented by concerned map. This map is called as an evaluation criteria map, attribute map, thematic map or data layer, which defined as a unique geographical attribute of the alternative decisions that can be used to evaluate the performance of the alternatives Malczewski, 1999.

2.3.2. Constraints

Constraint is limitation imposed by nature or by human being that do not permit certain actions to be taken Keeney, 1980 in Malczewski, 1999. It is important in determining the feasibility of the alternatives of decision. If decision is made which failed to take account the constraints, then the decision will be called infeasible or unacceptable decision. 8

2.3.3. Criteria Weighting

The purpose of criterion weighting is to express the importance of each criterion relative to other criteria Malczewski, 1999. In decision making, it is a common that each criterion is incommensurate or each criterion has influence level to decision result. There are some procedures to estimate weight, for example: rating, ranking, pair wise comparison method, trade-off analysis method, and so forth Malczewski, 1999.

2.3.4. Decision Rules