Z-Number extension of WASPAS
Z-WASPAS (Z-Number extension of WASPAS) is a ranking multi-criteria decision-making (MCDM) method introduced by Ghoushchi, S. J., Yousefi, S., Khazaeili, M. in 2021. It turns a decision matrix of alternatives scored on multiple criteria into a structured, reproducible result.
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When to use it
z-waspas extends WASPAS to handle Z-Number uncertainty. All arithmetic operations (normalisation, weighting, distance computation) are performed using Z-Number (Z = (A, B): restriction A, reliability B; both fuzzy) algebra. The final scores are defuzzified via convert to regular fuzzy: Ã = B·A, then centroid before ranking.
Strengths & limitations
- Follows a transparent, reproducible computational procedure that can be audited step by step.
- Handles multiple criteria of differing scales and units within a single decision matrix.
- May exhibit rank reversal when alternatives are added to or removed from the set.
- Assumes full compensation — a strong score on one criterion can offset a weak score on another.
Sources
- Ghoushchi, S. J., Yousefi, S., Khazaeili, M. (2021). Theory-Based Failure Modes and Effect Analysis for Medication Errors (Z-SWARA & Z-WASPAS). Journal of Healthcare Engineering DOI: 10.1155/2021/5533208 ↗
How to cite this page
ScholarGate. (2026, June 2). Z-Number extension of WASPAS. ScholarGate. https://scholargate.app/en/decision-making/z-waspas
Which method?
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