Statistical process control (SPC) requires collecting and analyzing data in real-time during production. Data integrity was a problem for Tier One automotive glass supplier, Guardian Industries (Auburn, IN), which supplies glass to clients such as DaimlerChrysler and GM.
According to Randy Miller, data systems technician for Guardian, gage er-rors and gage "fliers," in which gage readings fall outside reasonable boundaries, were part of the problem, as well as typographical errors made by operators entering data into the system.