Walter A. Shewhart altered the course of industry on May 16, 1924, with a historic memorandum to his superiors at Bell Laboratories, namely George D. Edwards. In this memorandum Shewhart proposed the control chart, a tool used to track process performance over time and to detect changes in parameters which can indicate a deterioration in quality. Joint schemes for the process mean and variance are essential to satisfy Shewharts dictum that proper process control implies monitoring both location and dispersion. Misleading signals (MS) can occur while using these joint schemes, and correspond...