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Ranking
qR-EDAS - q-Rung Orthopair extension of EDAS
q-Rung Orthopair outranking/ranking - q-Rung Orthopair Fuzzy Number (q-ROFN: μ, ν; μ^q+ν^q ≤ 1, q ≥ 1)
Yager, R. R.2017doi:10.1109/TFUZZ.2016.2604005 ↗
Overview
QR-EDAS follows Pattern B (Li-Wei-Lu 2019 + Liu-Wang 2018 + Keshavarz-Ghorabaee 2015 lineage): at F1 the q-ROFN matrix is reduced to crisp scores s_ij = μ_ij^q − ν_ij^q (Liu-Wang 2018 Def. 2.4). Cost criteria are handled at F1 by q-ROFN complement α^c=(ν,μ), equivalent to flipping the score sign. From F2 onwards the pipeline is identical to crisp EDAS (Keshavarz-Ghorabaee 2015): AV per criterion, PDA/NDA, weighted sums SP/SN, NSP/NSN normalisation, appraisal score AS=(NSP+NSN)/2. Rank descending by AS.
- Output
- utility, higher is better
- Data
- Q-Rung Orthopair Fuzzy, uncertainty tuples complete
- Weights
- Needs a weight source
- Size
- 2+ alternatives, 3-10 criteria works best
- Used for
- Q-Rung Orthopair Fuzzy MCDM, MAGDM under epistemic uncertainty, expert-driven evaluation with linguistic terms
How it works
- 1
Liu-Wang score reduction on q-ROFN decision matrix: s_ij = μ_ij^q − ν_ij^q ∈ [−1, 1]. Cost criteria use q-ROFN complement α^c = (ν, μ) before scoring (equivalently, score sign flips).
Liu-Wang 2018, Def. 2.4 score function; QR-EDAS.tex §Algorithmic Steps, Step 1
- 2
Average solution per criterion on score values: AV_j = s̄_j = (1/m) Σ_i s_ij.
QR-EDAS.tex §Algorithmic Steps, Step 2; Keshavarz-Ghorabaee 2015 Eq.(3) adapted to score domain
- 3
Positive (PDA) and negative (NDA) distance from AV. Benefit criteria: PDA rewards above-average, NDA penalises below-average. Direction handled at F1 via complement so both branches use the benefit form here.
QR-EDAS.tex §Algorithmic Steps, Step 3; Keshavarz-Ghorabaee 2015 Eqs.(4)-(5)
- 4
Weighted PDA and NDA sums across criteria.
QR-EDAS.tex §Algorithmic Steps, Step 4; Keshavarz-Ghorabaee 2015 Eqs.(6)-(7)
- 5
Normalise SP and SN by their per-method maxima.
QR-EDAS.tex §Algorithmic Steps, Step 4 (normalisation); Keshavarz-Ghorabaee 2015 Eqs.(8)-(9)
- 6
Appraisal score AS_i ∈ [0, 1] and descending ranking.
QR-EDAS.tex §Algorithmic Steps, Step 4 (AS); Keshavarz-Ghorabaee 2015 Eq.(10)
Fits when / Look elsewhere when
Fits when
- •Preserves q_rung_orthopair uncertainty through the pipeline rather than premature crispification at elicitation
- •Native group-decision support (multi-DM aggregation built into the pipeline)
Look elsewhere when
- •Crisp data sufficient - use base EDAS directly (avoid unnecessary uncertainty layer)
- •Aggregation operator (PFWA/PFOWA/etc.) not specified - output ambiguous
Assumptions to verify
- Decision matrix entries are valid q-Rung Orthopair Fuzzy numbers/tuples
- Underlying crisp method's compensation assumption holds in uncertain space
- All decision-maker(s) and experts use the same linguistic/uncertainty scale
Limitations
- •Rank reversal known on alternative-set changes (ref: inherited from crisp base; cf. Belton-Gear 1983, Wang-Luo 2009)
Edge cases and pitfalls
Value-space violation: ensure all entries satisfy μ^q + ν^q ≤ 1 with the analyst-specified q (q=1→IFS; q=2→PFS; q=3→FFS). DecisionMind requires a single q across the entire matrix.
Cost direction must be handled at F1 via q-ROFN complement (μ,ν)^c=(ν,μ), NOT applied to score sign later. Applying both double-flips and breaks ranking.
Degenerate AV: if s̄_j = 0 for some criterion (alternatives split symmetrically), PDA/NDA division by |s̄_j| explodes. DecisionMind falls back to s̄_j → max(|s̄_j|, ε) with ε=1e-9, recorded in P.edge_case_policies.
max SP = 0 or max SN = 0: NSP/NSN normalisation undefined. DecisionMind sets NSP_i=0 (no alternative exceeds AV) or NSN_i=1 (no alternative below AV), preserving the AS interpretation.
Works with
Commonly takes its weights from
How to cite
Yager, R. R. (2017). Generalized orthopair fuzzy sets. IEEE Transactions on Fuzzy Systems. https://doi.org/10.1109/TFUZZ.2016.2604005
System ID, as it appears in reports and the API
QR-EDAS