Pareto Analysis
Rank loss categories, calculate cumulative contribution and focus improvement on the few categories that dominate the selected measure.
Purpose and method
Rank losses or defects and identify the few categories responsible for the largest share of the effect.
When to use it
Use Pareto to prioritize limited improvement resources according to frequency, cost, time or another measurable impact.
Core principle
Pareto analysis prioritises consequences, not root causes. The ranking changes when the measure changes from count to cost, time, severity or another impact.
What the interactive module provides
- Ranked data table
- Pareto chart
- Cumulative percentage
- sorted Pareto chart, cumulative curve and selected priority categories
Professional verification: The module supports learning, analysis and documentation. Verify results against actual process conditions, internal standards, safety requirements and competent professional judgement before implementation.
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Recommended workflow
Rank loss categories, calculate cumulative contribution and focus improvement on the few categories that dominate the selected measure.
- 1
Define the decision and the impact measure
- 2
Clean and combine equivalent categories
- 3
Aggregate values for one comparable period
- 4
Sort descending and calculate cumulative share
- 5
Investigate the leading categories for causes
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Practical example
Scratch defects occur most often, but missing welds create the highest rework cost. Two Pareto charts lead to different but transparent priorities.
Calculation or verification principle
Category share = category value ÷ total value × 100%; cumulative share is the running sum after sorting categories from largest to smallest.
Required inputs → Expected outputs
- Required inputs
- consistent categories, selected impact measure, values and observation period
- Expected outputs
- sorted Pareto chart, cumulative curve and selected priority categories
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Common mistakes to avoid
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Mixing counts, costs and durations in one chart
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Using unstable category names
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Assuming the largest category is the root cause
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Applying an 80% cut-off mechanically
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Frequently asked questions
What data do I need to use this tool?
Prepare consistent categories, selected impact measure, values and observation period.
What result does the module produce?
The module produces sorted Pareto chart, cumulative curve and selected priority categories.
Can I implement the result without further review?
No. Treat the output as a structured engineering and improvement aid. Verify source data, assumptions, safety, quality, legal requirements and local process conditions with competent responsible people before implementation.
LEAN Toolbox
Open interactive tool →Pareto Analysis
Rank loss categories, calculate cumulative contribution and focus improvement on the few categories that dominate the selected measure.