Until the processes that generate the output become the focus of our efforts, the full power of these methods to improve quality, increase productivity, and reduce cost may not be fully realized.
—AIAG STATISTICAL PROCESS CONTROL MANUAL (SECOND EDITION)
Once you’ve made improvements, you’ll want to sustain (i.e., control) them to ensure that you stay at the new level of performance. Otherwise, you’ll gradually slip back to the old levels of performance. This is why you will want a process control system.
A process control system of flowcharts, control charts, and/or histograms can help you to monitor and maintain your new level of performance. Process control systems consist of
1. The system—suppliers, inputs, ...