Extension card · q-Rung Orthopair
q-Rung orthopair WASPAS (DecisionMind derivation)
This is the form of WASPAS that lets an exponent (q) set how large the support and rejection degrees given to a judgement can jointly be. The weighted-sum and weighted-product components are computed separately over these support-rejection pairs, and only the final step reduces them to a single score.
Base method
WASPAS →
Philosophy, mechanics, strengths and weaknesses are on the base method card; this card describes only the difference.
Data type (family)
q-Rung Orthopair →
What this data type is, when to use it, how to write it in a cell: the family's full account is here.
What Changes from the Base Method?
Four things change; the idea of blending a sum and a product does not.
Cells. In crisp WASPAS every cell is a single number. Here every cell is a pair: μ support degree, ν rejection degree. These two values must satisfy μ^q + ν^q ≤ 1; as q grows, the range of accepted pairs widens. In DecisionMind, q is not entered by the user; for this extension q = 3, and it comes bundled with the method's definition, unchangeable cell by cell.
Scale equalisation. Crisp WASPAS equalises every column by scaling it against its own best value. There is no such division step here, because support-rejection pairs are already between 0 and 1. Instead, μ and ν are swapped for a cost criterion. This operation does not equalise scale, it reverses direction.
Sum and product components. Crisp WASPAS's weighted sum (WSM) is matched here by the q-rung orthopair weighted average (q-ROFWA). Each alternative's support-rejection pair across the criteria is first reduced to a single pair. This pair is then turned, by the score function (s = μ^q − ν^q), into a single number called Q1. Crisp WASPAS's weighted product (WPM), in turn, is matched by the q-rung orthopair weighted geometric mean (q-ROFWG); the same score turns it into Q2. q-ROFWA magnifies support degrees optimistically, while q-ROFWG brings rejection degrees to the fore; this corresponds to the compensatory character of the sum and the penalising character of the product, respectively.
Result and combination. In crisp WASPAS, λ is a parameter adjustable in the interface between 0 and 1, defaulting to 0.5. In this extension λ is not offered as an interface field; it arrives as an additional input the engine accepts, with a default of 0.5, and can be changed through this additional input when needed.
DecisionMind fixes this direction correction, the q-ROFWA/q-ROFWG combination and the score s = μ^q − ν^q in QR-WASPAS; q comes from the method's definition, weights are taken from outside as fixed numbers, and the method does not generate weights.
How to Read the Output
The output is a combined score and a rank, as in crisp WASPAS; it is read the same way: it is not a percentage or a probability, and the ranking can shift when the alternative set changes.
The difference is this. The score blends an optimistic sum view (Q1) with a cautious product view (Q2); with which weight (λ) this blend is made does not show in the interface, and is 0.5 unless changed by the additional input. Beneath the score there is also a support-rejection pair, and this pair, under the constraint μ^q + ν^q ≤ 1 at q = 3, covers a wider area than Pythagorean fuzzy (q = 2). The gap between two scores depends on how much support and rejection was given on which criterion.
Thus instead of writing:
"According to QR-WASPAS, E2 is the best alternative"
the report should read:
"This score comes from combining the support-rejection pairs separately with q-ROFWA and q-ROFWG and blending them with λ=0.5; this lead depends on how much support and rejection was scored on which criterion, and can shift once the weights change"
When to Prefer This over the Base Method
Use this extension when experts give a judgement both very strong support and a very strong reservation at once, and these pairs also exceed the Pythagorean constraint (μ² + ν² ≤ 1). If expert pairs already fit within the intuitionistic or Pythagorean constraint, raising q brings no benefit; it only reduces discriminating power. It should be kept in mind that the whole matrix runs on a single q; the q a given cell requires is the q required by the most extreme pair in the matrix. The exit condition of crisp WASPAS holds here too: if no compromise is acceptable on one criterion, this extension too is fully compensatory.
Mistakes Specific to This Extension
Domain violation. Every cell must satisfy μ ∈ [0,1], ν ∈ [0,1] and μ^q + ν^q ≤ 1; q = 1 corresponds to intuitionistic fuzzy, q = 2 to Pythagorean fuzzy. Entering the calculation without checking this invalidates the method.
Choosing a large q without regard to the data. In this extension q is fixed and comes with the method's definition; asking for a different q "for flexibility" is not what this extension is for. If expert pairs exceed the range that q = 3 requires, this extension falls short and a method with a larger q is needed.
Writing ν as 1 − μ. In that case the sum is always exactly 1, and the extra acceptance range that q = 3 provides is never used at all.
Looking for λ in the interface. λ here is not an interface field like the weights; it arrives as an additional input with a default of 0.5. This distinction must be stated in the report; otherwise the reader may assume λ never changed at all.
The governing principle is this:
In QR-WASPAS, the support-rejection pair is combined and scored separately with q-ROFWA and q-ROFWG; q comes from the method's definition, it is not chosen cell by cell, and it is single for the whole matrix.
Cases
The first case is DecisionMind's validation example: since no shared QR-WASPAS application example exists in the literature, a synthetic three-alternative, three-criterion table has been built faithfully to the formula chain. The second case is an illustrative construction.
1. Illustrative example (DecisionMind's validation example): Choosing a base-station equipment supplier
A mobile network operator will choose one of three supplier proposals for next-generation base-station equipment. Three criteria apply: technical performance (more is better), ease of network integration (more is better), total cost of ownership (less is better). The technical board has reported both very strong support and very strong reservation for every supplier-criterion pair; because these pairs exceed the Pythagorean constraint (μ²+ν²≤1), the work was done at q = 3.
| Supplier | Technical performance | Ease of integration | Total cost (less is better) |
|---|---|---|---|
| E1 | (0.70; 0.40) | (0.50; 0.50) | (0.60; 0.50) |
| E2 | (0.80; 0.30) | (0.60; 0.40) | (0.40; 0.60) |
| E3 | (0.60; 0.50) | (0.70; 0.40) | (0.50; 0.50) |
| Weight | 0.40 | 0.35 | 0.25 |
The method swaps μ and ν in total cost, combines the three criteria's pairs separately with both q-ROFWA and q-ROFWG and scores them (s = μ³ − ν³), then blends the two scores with λ=0.5.
| Supplier | Combined score | Rank |
|---|---|---|
| E2 | 0.2809 | 1 |
| E3 | 0.1305 | 2 |
| E1 | 0.0859 | 3 |
The result reads as follows. E2 holds the highest support and lowest rejection pair (0.80; 0.30) on technical performance, the most heavily weighted criterion, and is also advantaged on total cost (once reversed). E3, though it holds the strongest pair on ease of integration (0.70; 0.40), does not have enough in this to offset E2's lead on technical performance. E1 and E3's base scores (0.0859 and 0.1305) sit closer to each other than to E2; the ranking between these two can easily change once the weight distribution changes.
The board's hesitation is this: what happens if the technical-performance weight is lowered from 0.40 to 0.05 and 0.65 is given to ease of integration (total cost staying at 0.30)? When the kernel is run directly and independently in Python, with these new weights E3's score falls to 0.1793 and E2's to 0.1682; first place passes to E3, because E3's advantage on ease of integration now determines the heaviest criterion.
In the report: "With the weights given (0.40; 0.35; 0.25), E2 has the highest combined score (0.2809). When the weight is shifted markedly to ease of integration (0.05; 0.65; 0.30), first place passes to E3; which criterion takes priority must therefore be separately justified."
Source: DecisionMind's QR-WASPAS validation example; since no shared QR-WASPAS application table exists in the literature, this was built synthetically, with expected results derived from the manifest's formula chain (direction correction, q-ROFWA/q-ROFWG combination, s = μ^q − ν^q score, q=3, λ=0.5). The value space rests on Yager's (2017) definition of the generalised orthopair fuzzy set. The scores and the weight-swap scenario were calculated independently by this card's author by running the kernel directly.
2. School canteen: A school's choice of canteen operator
A school parents' association will choose one of three candidate firms to run the canteen. Three criteria apply: commitment to the nutrition programme (more is better), hygiene record (more is better), monthly rent (less is better). The oversight board has reported, for every candidate-criterion pair, both a strong positive impression and a serious reservation at the same time; because some of these pairs also exceed the Pythagorean constraint, the evaluation was done at q = 3.
The method swaps μ and ν in the rent column, combines the three criteria's pairs with q-ROFWA and q-ROFWG, scores them, and blends them with λ=0.5. Suppose the candidate with the highest support on the nutrition programme also turns out to have a low reservation on the hygiene record, and comes out first.
The board's hesitation is this: for a candidate whose rejection degree on the rent criterion stays high, this reservation has dissolved into a single score. The board should separately report the rejection degree of the first-place candidate on the rent criterion and clarify it before signing.
In the report: "One candidate stands out on account of its commitment to the nutrition programme and hygiene record; this candidate's rejection degree on the rent criterion is higher than the others and must be separately addressed in contract discussions."
3. What Not to Do
In the illustrative example, writing E2's technical-performance pair, 0.80 and 0.30, with ν as 1 − μ, giving 0.80 and 0.20, is wrong; this erases the real reservation the board reported and wastes the extra acceptance range q = 3 provides. The second error is raising q to 5 "for more flexibility"; in this extension q is fixed and comes from the method's definition, it is not changed cell by cell or report by report. The third error is reporting E2's score of 0.2809 as "28 per cent suitability"; the score only ranks these three suppliers relative to one another.
Sources
For the formulas behind each step, the intermediate tables and citation formats, see the DecisionMind method page: decisionmind.app/library/qr-waspas
Zavadskas, E. K., Turskis, Z., Antuchevičienė, J., & Zakarevičius, A. (2012). Optimization of weighted aggregated sum product assessment. Elektronika ir Elektrotechnika, 122(6), 3–6. DOI: 10.5755/j01.eee.122.6.1810
Yager, R. R. (2017). Generalized orthopair fuzzy sets. IEEE Transactions on Fuzzy Systems, 25(5), 1222–1230. DOI: 10.1109/TFUZZ.2016.2604005
Liu, P., & Wang, P. (2018). Some q-rung orthopair fuzzy aggregation operators and their applications to multiple-attribute decision making. International Journal of Intelligent Systems, 33(2), 259–280. DOI: 10.1002/int.21927
Senapati, T., & Yager, R. R. (2020). Fermatean fuzzy sets. Journal of Ambient Intelligence and Humanized Computing, 11(2), 663–674. DOI: 10.1007/s12652-019-01377-0