In Control but Out of Specifications

[@sonandpets1215]

I am speechless with your knowledge Dr. Bill. Thank you for sharing it!

[@offroadpilots8890]

Very educational Bill and thank you for your dedication to SPC and processes. Just what I was looking for today for my aviation post.

[@pkennedyfk15]

Another option would be to increase the number of samples taken e.g. from individual samples to an average of 3 or 5 (if feasible). That way you will have a process that is in control and minimise the risk of operators over-adjusting to meet a specification that the process is not capable of meeting for individual values. The variation that the customer gets does not change but for internal controls it helps operators.

[@SPCforExcel]

Yes that is another option, but you will still have the issue of the process not meeting specs for individaul values. Subgrouping the results will not change that but will help the operators not to respond to out of control individual charts.