Having identified the general problem area, we need to gather data that will enable us to pinpoint specific causes. One simple tool that could be used for this is a tally chart that was introduced in the section on presenting data.
|Sags / Runs|
In the section on u-Charts we saw how a u-Chart for Multiple Characteristics could also be used as a data source for Pareto analysis. In that case, during the inspection process, the defect data for a sample was recorded (on a tally chart) and then, when the sample was complete, the information was transferred onto the u-Chart.
In the following example, we will be using data from a completed u-Chart as the source for our Pareto analysis, but we could just as easily use a tally chart like the one shown above (which contains exactly the same data).