Quality Tools
Pareto Chart Generator
Rank problems by frequency, cost, or impact and see the cumulative line — the 80/20 view that tells you where to start.
Manufacturing Defects Analysis
80/20 Analysis
Vital Few: 4 categories (80.0%)
Impact: 91.1% of total value
Top Category: Soldering Defects (32.5%)
Summary Statistics
Total Categories: 5
Total Value: 753
Average per Category: 150.6
| Rank | Category | Value | % | Cum. % |
|---|---|---|---|---|
| 1 | Soldering Defects | 245 | 32.5% | 32.5% |
| 2 | Component Placement | 187 | 24.8% | 57.4% |
| 3 | Circuit Traces | 156 | 20.7% | 78.1% |
| 4 | Contamination | 98 | 13.0% | 91.1% |
| 5 | Labeling Errors | 67 | 8.9% | 100.0% |
💡 Improvement Recommendations
Focus your improvement efforts on the top 4 categories: Soldering Defects, Component Placement, Circuit Traces, Contamination. These represent 91.1% of your total impact and offer the greatest return on investment for process improvements.
📈 How to Use Pareto Charts Effectively
• Focus on the vital few: The 80/20 rule - 80% of problems come from 20% of causes
• Prioritize improvements: Address the highest bars first for maximum impact
• Use real data: Base your analysis on actual measurements, not assumptions
• Regular updates: Update charts periodically to track improvement progress
• Team involvement: Share results with teams to focus improvement efforts
• Root cause analysis: Use fishbone diagrams to dig deeper into top categories
Understanding Pareto charts
A Pareto chart is a type of chart that contains both bars and a line graph, where individual values are represented in descending order by bars, and the cumulative total is represented by the line. It is named after Italian economist Vilfredo Pareto.
The Pareto principle (80/20 rule) states that roughly 80% of effects come from 20% of causes. In quality management this often means:
- 80% of problems are caused by 20% of defect types
- 80% of costs come from 20% of issues
- 80% of customer complaints relate to 20% of product features
- 80% of delays are caused by 20% of bottlenecks
How to create a Pareto chart
- Identify and list the problems or categories to analyse
- Collect data on frequency, cost, or impact for each category
- Arrange categories in descending order by magnitude
- Calculate cumulative percentages
- Draw the chart with bars and the cumulative line
- Identify the “vital few” causing most of the problem
Best practices:
- Use consistent time periods for data collection
- Make categories mutually exclusive and actionable
- Update the chart as improvements are made
- Consider several measures — frequency, cost, impact — as they can rank causes differently
- Follow up with root cause analysis on the top categories
Pareto chart applications
| Area | Typical uses |
|---|---|
| Quality management | Defect types, customer complaints, supplier quality issues, non-conformances |
| Operations | Downtime causes, safety incidents, process bottlenecks, waste |
| Business analysis | Sales by product, cost reduction opportunities, satisfaction drivers |
Worked example: electronics assembly defects
An illustrative month of defect data from an electronics assembly line, sorted for a Pareto chart:
| Defect type | Count | Share | Cumulative |
|---|---|---|---|
| Soldering defects | 245 | 30.1% | 30.1% |
| Component placement | 187 | 22.9% | 53.0% |
| Circuit traces | 156 | 19.1% | 72.1% |
| Contamination | 98 | 12.0% | 84.2% |
| Labelling errors | 67 | 8.2% | 92.4% |
| Packaging damage | 34 | 4.2% | 96.6% |
| Others | 28 | 3.4% | 100.0% |
The top three categories account for 72.1% of the 815 defects, and soldering alone for 30.1%. That makes the soldering process the first target for root cause analysis — a fishbone diagram is the natural next step.