Free quality tool
Pareto Chart Builder
Identify the few categories contributing most to your quality problem with a free Pareto Analysis.
- Free
- No registration
- No installation
Your data
Example data is sample content for demonstration. Replace it with your own observations before drawing conclusions.
Your Pareto Analysis
Enter at least two categories with positive values to see the sorted table, the cumulative percentages and the Pareto chart here.
What is Pareto Analysis?
Pareto Analysis is a prioritization method. Observations are grouped into categories, each category is measured with an additive value such as defect count, cost or downtime, and the categories are then sorted from the largest contribution to the smallest. The Pareto Chart shows these categories as descending bars with a cumulative percentage line, so a team can see how concentrated the problem really is.
Pareto Analysis helps identify the categories contributing most to the observed total. The well-known 80/20 principle is a useful heuristic, not a guaranteed result.
What is the 80/20 rule?
The Pareto Principle often describes situations where a relatively small share of causes or categories contributes a large share of outcomes. It is not a requirement that every dataset equals exactly 80/20. Some quality datasets are strongly concentrated in one category; others are almost evenly distributed. The 80% reference line in the chart is a reading aid for your actual data, not a target.
How to create a Pareto Chart
- Define clear, non-overlapping categories.
- Collect an additive measure for each category — occurrences, cost, downtime or quantity.
- Total the observed values.
- Sort the categories in descending order.
- Calculate each category percentage of the total.
- Calculate the cumulative percentage down the sorted list.
- Identify the largest contributors.
- Investigate those categories with a causal method.
Pareto Analysis example
A final inspection station records 100 defects in one month: surface scratch 42, missing component 25, wrong label 18, dimensional defect 9 and other 6. Sorted descending, the cumulative percentages are 42.0%, 67.0%, 85.0%, 94.0% and 100.0%. Cumulative contribution first passes 80% at the third category, so surface scratch, missing component and wrong label together account for 85.0% of the observed defects — that is where the investigation starts.
When to use a Pareto Chart
- Defect categories from inspection or final test.
- Customer complaints and warranty claims.
- Supplier defects and incoming quality issues.
- Scrap and rework reasons.
- Machine downtime causes.
- Audit findings and recurring process losses.
What Pareto Analysis does not tell you
A Pareto Chart ranks what was observed. It does not prove root cause, it does not explain the failure mechanism and it does not predict how much of the problem a corrective action will remove. Category definitions and data quality also shape the result: poorly defined categories produce a misleading chart.
Pareto vs 5 Why
Pareto prioritizes; 5 Why investigates. Use the chart to decide which category deserves attention, then follow one causal chain with the free 5 Why builder.
Pareto vs Fishbone
Pareto ranks observed categories using data. A Fishbone Diagram explores possible causes across cause families before any of them is verified. They answer different questions and work well in sequence.
Pareto in 8D
Pareto Analysis can help focus an investigation or prioritize recurring categories, but it is not itself the 8D process. When an issue needs containment, verified root cause, corrective action and prevention, move into the 8D workspace. You can also review the broader quality problem solving methods or model event combinations with Fault Tree Analysis.
Frequently asked questions
- What is a Pareto Chart?
- A Pareto Chart is a bar chart of categories sorted from the largest contribution to the smallest, combined with a line showing the cumulative percentage of the total.
- What is Pareto Analysis?
- Pareto Analysis is a prioritization method. It ranks categories by how much they contribute to an observed total so a team can decide where to look first.
- What is the 80/20 rule?
- The Pareto Principle describes the common observation that a relatively small share of categories often contributes a large share of the total. It is a heuristic, not a law.
- Does Pareto always mean 80% of problems come from 20% of causes?
- No. Real datasets vary. Some are highly concentrated, others are nearly flat. The chart shows the actual distribution of your data; the 80% reference line is only a reading aid.
- How do you calculate cumulative percentage in a Pareto Chart?
- Sort the categories descending, add each category value to a running total, then divide that running total by the overall total and multiply by 100.
- Can I use Pareto Analysis for quality defects?
- Yes. Defect categories, complaints, scrap reasons, supplier issues, audit findings and warranty claims are all typical inputs.
- Can I use Pareto Analysis for cost or downtime?
- Yes. Any additive measure works — occurrences, cost, downtime minutes or quantity. Select the measure above the table.
- Does Pareto Analysis identify root cause?
- No. It prioritizes observed categories. It does not explain why a problem occurs and it does not prove causality.
- What should I do after Pareto Analysis?
- Investigate the largest contributors with 5 Why, a Fishbone Diagram or Fault Tree Analysis, and use 8D when formal containment, corrective action and prevention are required.
- Is the Qhubio Pareto Chart Builder free?
- Yes. Data entry, calculation, the chart and the interpretation are free, with no registration, installation or payment.
- Do I need an account?
- Only if you want to save the analysis to your Qhubio workspace and open it again later.
- Can I save my Pareto analysis?
- Yes. Click Save analysis. If you are not signed in, Qhubio holds the analysis while you sign up and saves it to your workspace afterwards. Unsaved analyses are not kept after you leave or refresh the page.