Minitab Connect offers several control charts and capability analyses for you to monitor your processes. Choose which control chart or capability analysis to use based on whether you have continuous or attribute data.
Use an NP chart to monitor the number of defective items where each item can be classified into one of two categories, such as pass or fail.
Use a C chart to monitor the number of defects where each item can have multiple defects. You should use a C chart only when your subgroups are the same size.
Overdispersion can cause a traditional P chart to show an increased number of points outside the control limits. Underdispersion can cause a traditional P chart to show too few points outside of the control limits. The Laney P' chart adjusts for these conditions.
Overdispersion can cause a traditional U chart to show an increased number of points outside the control limits. Underdispersion can cause a traditional U chart to show too few points outside of the control limits. The Laney U' chart adjusts for these conditions.
Use Normal Capability Analysis to evaluate the potential (within) and overall capability of your process based on a normal distribution.
Use Between/Within Capability Analysis to evaluate the capability of your process based on a normal distribution when your process naturally produces systemic variation between subgroups, such as a batch process.
Use Poisson Capability Analysis to determine whether the rate of defects per unit (DPU) meets customer requirements. Use this analysis when you count the defects on each item, and each item can have more than one defect.