It is similar to the weighted sum model (WSM) in that it produces a simple score, but has the very important advantage of overcoming the issue of 'adding apples and pears' i.e. adding together quantities measured in different units.
The weighted product approach does not require any normalization because it uses multiplication instead of addition to aggregate the data.
The WPM is often called dimensionless analysis because its mathematical structure eliminates any units of measure.
This simple decision problem is based on three alternatives denoted as A1, A2, and A3 each described in terms of four criteria C1, C2, C3 and C4.
An alternative approach with the WPM method is for the decision maker to use only products without the previous ratios.
[1][2] That is, to use the following variant of main formula given earlier: In the previous expression the term P(AK) denotes the total performance value (i.e., not a relative one) of alternative AK when all the criteria are considered simultaneously under the WPM model.
Some interesting properties of this method are discussed in the 2000 book by Triantaphyllou on MCDA / MCDM.
Scoring methods such as WSM and WPM may be used for rankings (universities, countries, consumer products etc.
[6] The tutorial article by Tofallis describes its advantages over the weighted sum approach.