Lexicographic Best Worst Method
Also known as: Lexicographic BWM
Lexicographic BWM combines the strengths of the Best Worst Method with lexicographic (sequential) optimization. Instead of weighting all criteria simultaneously, it assigns criteria to priority levels, solves the BWM for the highest-priority criteria first, then solves for lower-priority criteria while keeping the higher-priority weights fixed. This ensures that higher-priority criteria are never sacrificed to improve lower-priority ones.
Key highlights
- Ensures priority hierarchy is maintained; high-priority criteria are never sacrificed for marginal gains in lower-priority criteria
- Reduces cognitive burden; best-worst comparisons are conducted separately for each priority level, making each comparison set smaller
- Transparent decision rationale; different priority levels can be explained to different stakeholders
- Robust to preference inconsistency; if lower-priority comparisons are inconsistent, high-priority criteria are unaffected
Intuition
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How it works
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When to use it
Use Lexicographic BWM when criteria have a clear hierarchical importance structure and when maintaining the priority hierarchy is essential. It is ideal for organizational decisions with must-have vs. nice-to-have criteria, policy decisions with fundamental vs. secondary objectives, and any situation where decision-makers want to guarantee that high-priority criteria are not compromised.
Strengths & limitations
- Ensures priority hierarchy is maintained; high-priority criteria are never sacrificed for marginal gains in lower-priority criteria
- Reduces cognitive burden; best-worst comparisons are conducted separately for each priority level, making each comparison set smaller
- Transparent decision rationale; different priority levels can be explained to different stakeholders
- Robust to preference inconsistency; if lower-priority comparisons are inconsistent, high-priority criteria are unaffected
- Lexicographic solutions can be extreme; once a high-priority criterion is optimized, lower-priority criteria may be very poorly satisfied
- Requires explicit priority classification; ambiguity in priority levels leads to different solutions
- Sensitive to priority structure; reassigning a criterion from priority level 1 to level 2 can dramatically change the final weights
- May produce dominated alternatives; in some cases, the final solution could be improved by trading off high-priority criteria slightly
Common pitfalls
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Applications
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Frequently asked
How many priority levels should I use?
Typically 2-3 levels are optimal. More levels increase cognitive complexity without proportional benefit. If you need more granularity, use weights within each level to express finer distinctions.
What if criteria at the same priority level disagree on best/worst?
This is normal and reflects trade-offs. Conduct sensitivity analysis: solve with different best/worst assignments and see how results change. Present multiple scenarios to stakeholders.
Can I move criteria between priority levels if results don't make sense?
Yes, but this should be done intentionally with stakeholder input, not reactively based on results. If results surprise you, first investigate whether the priority assignment truly reflects values, or whether the BWM best/worst comparisons were inconsistent.
Sources
- 1.Rezaei, J. (2015). Best-worst multi-criteria decision-making method: Some properties and a linear model. Journal of Cleaner Production, 229, 976-985.
- 2.Khanmohammadi, E., & Kazemi, M. (2019). A preference aggregation method based on the comparative advantage of each individual. Applied Soft Computing, 75, 298-310.
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Cite this page
ScholarGate. (2026, June 3). Lexicographic Best Worst Method. ScholarGate. https://scholargate.app/decision-making/lexicographic-bwm