Hey everyone, welcome to this lecture. What is a pie chart? a pie chart is used when you are capturing defectives. And when the subgroup size varies. a pie chart tracks the proportion defective and detects the presence of special causes. Let's look at this example.

As a quality auditor you are required to audit a certain percentage of transactions each month you capture the defective transactions out of the total transactions audited every month, the total volume of these transactions varies. You have collected the data for last 28 days create a control chart and identify if the process is in control. In this example, you're capturing defectives and the sample size varies this you will use a p chart, but how will you construct that feature? Let's learn that in the next lecture.