Control Chart Failure
The Control Chart is a failure. It is an old technology that was valuable in its day, however in today’s world, it should have no place.
If you are operating at 3 sigma then it works because the Control Chart is a technology that is optimized for 3 sigma operations. In the 21st-century, if you are still running at 3 sigma, that means that you are generating 66,800 errors per million opportunities. Passing errors to your customers is embarrassing if they’re obvious, but catastrophic if they’re buried. Also, if you’re running at 3 sigma, you’re leaving significant money on the table.
When I say the Control Chart is a failure it’s because it is optimized for 3 sigma. For instance, there are sequences that you look for that supposedly give you information. If you are not operating at 3 sigma then those signals will be erroneous. Also, there are requirements for data that become onerous for your Control Chart to work if you’re running above three sigma.
In this presentation, I go into more detail: