Dominance and Pareto elimination
Delete any option that another option beats on every criterion, which shrinks the set for free and before any weighting.
- Time cost
- 15 min
- Output
- The Pareto set and a list of what was deleted and why.
- Steps
- 5
Use when
- You have more than three options and have not yet scored anything.
- Before any weighted method — it is strictly cheaper.
- You want a defensible reduction that involves no preference judgements at all.
Do not use when
- Only two or three options exist; you can see dominance by eye.
- Every option wins on something, which is the common case and means this step produces nothing.
Inputs required
- Options
- Criteria
- A rough ordering per criterion — exact values are not needed
Procedure
- 01
Order within each criterion
You only need rank, not score. Which option is best on cost, second, third. Repeat per criterion.
- 02
Check each pair
Option X is dominated if some option Y is at least as good on every criterion and strictly better on at least one.
- 03
Delete the dominated
No weighting needed and no judgement about what matters. Whatever your preferences, you would never choose a dominated option.
- 04
Check practical dominance
Where an option is beaten on everything except a criterion by a trivial margin, treat it as dominated too. State the margin you are ignoring so the shortcut is visible.
- 05
Report what is left
The survivors are the Pareto set. Every one of them is best under some set of weights, which is exactly why weighting now matters.
Characteristic failure mode
Worked example
Six candidate suppliers on four criteria.
- 01Rank each supplier on price, lead time, defect rate, exit terms.
- 02Two suppliers are beaten by one particular supplier on all four.
- 03A third is beaten on three and is within 1% on the fourth — practical dominance, margin stated.
Result
Six options become three, before a single weight is argued about. The remaining three genuinely trade off against each other.
Where to go next