Run ChartsRun chart gives the trend of processes - its performance over a period of time; against previous performance. Run charts help in spotting aberrations in process performance and its progression over time. We can add an average line (parallel to the X axis) to the Y values to see the data deflection from average.
We can also have multiple run charts where the trends of process compliance of several projects can be compared.
Since run charts depict process trends, significant trends or patterns can be identified and investigated for the root causes. Similarly, special variations (significant deviant data points) can be spotted and their causes identified & addressed.
The above chart does not tell anything about the tolerance limits of PCI (that the organization would put up with). It merely tells us about the PCI trend for the months stated. So, without a guiding process performance limits, it is not of much use.
What is the difference between run chart and control chart?
ReplyDeleteThe last paragraph of the write up precisely sums up the difference. "The above chart does not tell you anything....". The tolerance limits or the UCL/LCL is what distinguishes a control chart from a run chart. A control chart will help you understand the process performance - whether it is within or out of control / stable or otherwise.
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