Based on the data given below, which of the following control charts would you like to use to devise a control mechanism?
Based on the data given below, which of the following control charts would you like to use to devise a control mechanism?
The p-chart is the appropriate control chart to use because it measures the proportion of nonconforming units in a sample. In this case, you are dealing with the proportion of reports that were not delivered on time out of the total number of reports that were supposed to be delivered each day. By using the p-chart, you can effectively monitor and control the quality by looking at the percentage of reports delivered on time, which provides a more meaningful analysis compared to just counting the number of reports delivered late.
Telling your boss just the number of undelivered/defective reports does not make sense. It is like saying - we were not able to deliver 10 reports. But your management needs to know the total number of reports to be delivered, the ratio of undelivered report is 10/10 or 10/100 or 10/1000. If the ratio is 10/10, then that is a big issue, but if the ratio is 10/100, then it may not be a big issue. Therefore, instead of plotting number of undelivered reports, it is better to plot the portion of the total reports undelivered, for example - 10% of the reports were not delivered. The proportion will be a better measure to assess than the number of undeliverable reports.