säätökaaviossa

Säätökaaviossa, also known as a control chart, is a statistical process control tool used to determine whether a manufacturing process is in a state of statistical control. It was developed by Walter A. Shewhart in the 1920s. The chart typically consists of a centerline, which represents the average of the process, and upper and lower control limits, which are usually set at three standard deviations from the centerline. Data points are plotted on the chart over time, and if the points fall within the control limits, the process is considered to be in control. If the points fall outside the control limits, it may indicate that the process is out of control and requires investigation and corrective action.

There are several types of control charts, including the X-bar and R chart, which are used to monitor the mean and range of a process, and the p-chart, which is used to monitor the proportion of defects in a process. Control charts are widely used in quality control and process improvement to ensure that products meet customer requirements and to identify and eliminate sources of variation in a process.

The effectiveness of control charts depends on the accuracy of the data used to construct them and the appropriate selection of control limits. It is important to note that control charts are not a substitute for understanding the underlying process and its variables. They should be used as a tool to monitor and improve the process, rather than as a means of making decisions about the process.

In summary, säätökaaviossa is a powerful tool for monitoring and improving manufacturing processes. By plotting data points over time and comparing them to control limits, users can determine whether a process is in control and take appropriate action to ensure that it remains so.