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Weighting
Z-AHP - Z-Number Analytic Hierarchy Process
Hierarchical pairwise comparison weighting under Z-number uncertainty
Nuriyev, M.2020doi:10.32479/ijeep.9950 ↗
Overview
Z-AHP outputs criterion importance weights (sum=1). Higher weight = more important. Pair with any alternative-ranking method (Z-TOPSIS, Z-PROMETHEE per Nuriyev's hybrid) that consumes a weight vector. For multi-level hierarchies, compute weights level-by-level and combine via Saaty's hierarchical aggregation.
- Data
- Z-Number
- Weights
- Derived internally, no weight source needed
How it works
- 1
Step 1
- 2
Step 2
- 3
Step 3
- 4
Step 4
- 5
Step 5
- 6
Step 6
- 7
Step 7
- 8
Step 8
- 9
Step 9
Fits when
- •Hierarchical decomposition enables complex problems (Nuriyev demonstrates goal → 4 main criteria → 9 sub-criteria)
- •Captures both vagueness (TFN) and reliability (second TFN) - richer than Buckley fuzzy AHP
- •Buckley's geometric mean is well-established and avoids iterative eigenvector computation
- •Group decision-making built-in via per-cell arithmetic averaging (Eq.25)
Edge cases and pitfalls
- •When all cells are (1,1,1)+(VH,VH), weights are uniform 1/n
- •When K=1, group aggregation is identity - pipeline unchanged
- •Two-level hierarchy: compute weights per level, then composite = main × sub (Nuriyev Table 12)
- •Reciprocity slightly violated: auto-correct or warn
- •n very large (>12): pairwise burden - switch to Z-BWM (2n-3 comparisons)
Forgetting reciprocity Eq.(5) when entering only upper triangle - implementation must auto-fill lower triangle.
Confusing Z-AHP COA defuzzification (Eq.30, simple average of l,m,u) with GMIR (weighted average using m·4). Nuriyev uses COA, NOT GMIR.
Applying Buckley geometric mean to AGGREGATED Z-vectors before Z→TFN - must do Z→TFN FIRST then geometric mean.
Treating reliability TFN as restriction TFN - they are TWO separate fuzzy components per Z-number.
Collapsing each expert's judgement to a crisp number (or averaging the raw Z-numbers) before Eq.(25): the paper converts every expert's Z-number to a regular TFN first (Eq.6-8), averages the TFNs cell by cell, and only defuzzifies the final fuzzy weights (Eq.30).
Works with
How to cite
Nuriyev, M. (2020). Z-numbers Based Hybrid MCDM Approach for Energy Resources Ranking and Selection. International Journal of Energy Economics and Policy. https://doi.org/10.32479/ijeep.9950
System ID, as it appears in reports and the API
Z-AHP