o establish upper and lower control limits $($UCL and LCL$)$ for a given set of values, particularly when monitoring processes for defects, a common method is using control charts. The control chart provides a visual representation of how a process varies over time and helps determine if a process is in control or out of control. To calculate UCL and LCL$,$ you need to determine the mean and standard deviation of the data, then use these to calculate the control limits$.$