Select The Best Definition Of A Control Chart
Introduction:
A control chart is a statistical tool to monitor a process and to determine if it is under control or not. It is used to distinguish between random variation and special causes of variation in a process. This article will help you select the best definition of a control chart.
What is a Control Chart?
A control chart is a graphical representation of data that has been collected over time. The chart shows the average value of the data, as well as upper and lower control limits. The control limits are calculated based on the variation in the data. If the data falls within the control limits, the process is considered to be under control. If the data falls outside the control limits, the process is considered to be out of control.
Types of Control Charts:
There are several types of control charts, including:
- X-bar and R chart
- X-bar and S chart
- P chart
- NP chart
- C chart
- U chart
X-bar and R Chart:
The X-bar and R chart is used to monitor the process mean and the process variation. The X-bar chart shows the average value of the data, while the R chart shows the range of the data. If the data falls within the control limits, the process is considered to be under control.
X-bar and S Chart:
The X-bar and S chart is used to monitor the process mean and the process variation. The X-bar chart shows the average value of the data, while the S chart shows the standard deviation of the data. If the data falls within the control limits, the process is considered to be under control.
P Chart:
The P chart is used to monitor the proportion of nonconforming items in a sample. The chart shows the proportion of nonconforming items, as well as upper and lower control limits. If the proportion of nonconforming items falls within the control limits, the process is considered to be under control.
NP Chart:
The NP chart is used to monitor the number of nonconforming items in a sample. The chart shows the number of nonconforming items, as well as upper and lower control limits. If the number of nonconforming items falls within the control limits, the process is considered to be under control.
C Chart:
The C chart is used to monitor the number of defects per unit. The chart shows the number of defects, as well as upper and lower control limits. If the number of defects falls within the control limits, the process is considered to be under control.
U Chart:
The U chart is used to monitor the number of defects per unit when the sample size varies. The chart shows the number of defects per unit, as well as upper and lower control limits. If the number of defects per unit falls within the control limits, the process is considered to be under control.
Conclusion:
A control chart is a powerful tool for process improvement. It helps to identify when a process is out of control and when action needs to be taken. There are several types of control charts, including the X-bar and R chart, X-bar and S chart, P chart, NP chart, C chart, and U chart. By selecting the best definition of a control chart, you can use this tool to improve your processes and achieve better results.