When using a control chart one should gather data in six sigma?

When using a control chart in Six Sigma, it's essential to gather data that is representative of the process being monitored. Typically, data should be collected over a sufficient period to capture variations and ensure statistical significance. Ideally, data points should be collected in subgroups, allowing for analysis of trends and patterns. This helps in identifying whether the process is stable and in control, or if there are any signals of variation that need to be addressed.