Hey everyone. Welcome to this lecture control chart selection for discrete data. To begin with, let's discuss four examples. Example one, a team is tracking the number of applications that come in with incomplete information. Each day, they pull a random sample of 50 applications and review them for completeness. They plot the number that are incomplete.
In this example, the team is not tracking incomplete fields, they are tracking the number of applications that that come in with incomplete information. In other words, they are not tracking defects but they are tracking defectives. Additionally, they are reviewing a fixed sample of 50 applications each time. So the subgroup size is fixed. Example to a team is tracking the number of applications that come in with income Read information. Each day, they review all applications for completeness and plot the percent that are incomplete.
In this example, the team is still tracking defectives, but the subgroup size differs. Example three, a team is tracking the number of incomplete fields on applications. Each day, they pull a random sample of 50 applications and review them for completeness. They plot the total number of fields that are incomplete. In this example, the team is tracking the number of incomplete fields on applications. In other words, they are tracking defects.
In addition to that, each day, they pull a random sample of 50 applications and review them so they have a fixed subgroup size that they monitor each day. Example for another person Sona is tracking the number of fields that are incomplete on applications. Each day her team reviews all incoming applications for completeness and plots the number of incomplete fields per number of applications. In this example, the team is still tracking incomplete fields that is their tracking defects. However, they are not tracking a fixed subgroup size Rather, they are reviewing all incomplete applications that is, their subgroup size varies. So, to select the right control chart, you will first identify if the data that you are plotting is continuous or discrete.
If it is discrete, you will identify the type of flow counted that is, whether you're capturing defects or defectives, you will finally identify if the subgroup size remains the same or it varies every time based on these observations, you will decide which control chart to be used. For example, one where you're capturing defectives and the subgroup size is the same, you will use an NP chart, for example to where you're capturing defectives and the subgroup size varies, you will use a p chart. So for example three where you're capturing defects and the subgroup size is the same, you will use a C chart. And finally, example for where you're capturing defects and the subgroup size varies, you will use a u chart. Let me now put this information in the form of a chart. This is how it looks.
And this is how you select control charts for discrete data. I have added this chart in the resources section of this lecture for you to download and use. If you have any questions, please feel free to share with me on the q&a discussion board. I will We'll be happy to respond and help clarify those questions. It is time for an activity to select the right control chart for the right situations. You will go through it in the next lecture.
Thank you for attending. See you in the next one.