When a second parameter may be important, the Pareto chart should be redrawn to assess its impact. This may well result in a different order of priority. When all the factors are taken into account, an informed decision can be taken on prioritising problem-solving activities.
In this example we are using an estimate of the cost per occurrence of each defect type as the second parameter. This gives us an estimate of the total cost per defect type, based on the number of occurrences. Each defect is then given a ranking based on the estimated total cost. The new information is summarised in the table below.
| Defect | Frequency | Cost | Total | Rank |
|---|---|---|---|---|
| Sags/Runs | 35 | 2.50 | 87.50 | 4 |
| Orange Peel | 30 | 1.00 | 30.00 | 7 |
| Blisters | 4 | 5.00 | 20.00 | 10 |
| Scratches | 3 | 10.00 | 30.00 | 8 |
| Overspray | 3 | 150.00 | 450.00 | 1 |
| Flotation | 3 | 26.00 | 78.00 | 5 |
| Gun Spits | 2 | 14.00 | 28.00 | 9 |
| Off Colour | 1 | 300.00 | 300.00 | 2 |
| Dirt | 1 | 35.00 | 35.00 | 6 |
| Dull Finish | 1 | 175.00 | 175.00 | 3 |
Using these values, try drawing a new Pareto chart to compare with the previous one. Once again, you can print out a blank chart to work on, or create your own chart from scratch.
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