{"id":1809,"date":"2022-10-16T12:21:40","date_gmt":"2022-10-16T12:21:40","guid":{"rendered":"https:\/\/mbithiguide.com\/?p=1809"},"modified":"2022-10-21T09:17:25","modified_gmt":"2022-10-21T09:17:25","slug":"cusum-control-chart","status":"publish","type":"post","link":"https:\/\/mbithiguide.com\/cusum-control-chart\/","title":{"rendered":"How to Set up Cummulative Summation (CUSUM) Control Chart"},"content":{"rendered":"\n

Definitions<\/h2>\n\n\n\n


A cumulative summation control chart is a type of control chart that is used to monitor changes in a process over time. This chart is used to detect small changes in the process that may not be detectable with other types of control charts. It is especially useful when monitoring processes that are difficult to control using traditional Shewhart control charts, such as those with large process variability or rare events.<\/p>\n\n\n\n

The chart is constructed by plotting the cumulative sum of the deviations of each data point from the mean. If the process is in control, the plot will be a horizontal line. If the process is not in control, the plot will be a curved line.<\/p>\n\n\n\n

The cusum control chart is based on the cumulative sum (cusum) of deviations from a target value. The target value can be the mean of a process distribution, or a specification limit. The cusum is calculated at each observation, and if it exceeds a pre-determined threshold, an out-of-control condition is indicated.<\/p>\n\n\n\n

Just like the Xbar and R chart<\/a>, the CUSUM chart<\/a> is used to plot time series data, so the chart is meant to alert users to significant changes in process performance.<\/p>\n\n\n\n

CUSUM charts do not plot raw data values, averages, ranges or standard deviations. Instead, plot points on a cusum chart are data values roughly representative of the cumulatively summed, subgroup to subgroup deviations from a specified target or production mean. <\/p>\n\n\n\n

There are several advantages to using a cumulative sum (CUSUM) control chart over other types of control charts. One advantage is that CUSUM charts are more sensitive to small changes in the process mean than other control charts<\/a>, such as Shewhart control charts. This means that CUSUM charts can be used to detect process changes more quickly. <\/p>\n\n\n\n

Another advantage of CUSUM charts is that they can be used to monitor processes that are not in statistical control. This is because the CUSUM chart is based on the cumulative sum of deviations from the target value, rather than on the individual data points. This makes CUSUM charts more robust to changes in the process distribution. <\/p>\n\n\n\n

CUSUM charts can be used to estimate the process mean, even when the process is not in statistical control. This is because the CUSUM chart is based on the cumulative sum of deviations from the target value, which is an estimate of the process mean.<\/p>\n\n\n\n

Setting up a CUSUM Control Chart<\/h2>\n\n\n\n

When compared with traditional control charts, the tabulated CUSUM chart is unique, and certain parameters and statistics must be used in its creation.<\/p>\n\n\n\n