Why to use PROMETHEE / GAIA instead of AHP?
The methods PROMETHEE and GAIA present countless advantages over AHP. AHP is based on a principle of pair-wise evaluation of alternatives, according to a built-in scale valued from 1 to 9. So, for every pair of alternatives and every used criterion, the user has to indicate his preference of an alternative on every other. If, such as recommended within the framework of AHP, the user makes a decomposition downward from the generic to the specific, it will force the user to perform a huge number of comparisons and to remain coherent by establishing the relations of dominance. This last point is commonly viewed as a major problem with AHP. For example, if A is preferred to B with a note of 6 on 9 and, B to C with a note of 4 on 9, does it mean that A have to be preferred to C with a note of 4×6=24 on 9×9=81? And as AHP imposes a built-in scale of 9 values, how to characterize the dominance of A on C by remaining consistent with A/B=6 AND B/C=4. AHP imposes so on the user to worry about th
