I am watching the STIPS course on quality methods as I want to start making control charts, and I noticed that they said the x-axis should be regular time intervals. I want to use control charts to monitor the controls in a test method, but we do not run this method on regular time intervals. Instead, we run the test whenever sample is available. And it would be costly/impractical to run the test at regular intervals at this time.
I am wondering what consequences, if any, we'll experience if the data fed into the control chart is collected at irregular time intervals.
Thanks for your help!
