TPS transportability: control charting ATE

Test Program Sets, TPS, designed to run on automatic test equipment, ATE, should produce identical results when moved. Sometimes this does not happen. To answer stability questions we have control charted the various ranges of the DMM, for three different IFTE Base Shops. The data range over approximately 260 days producing eight (8) points. Averages of three points and their repeatability´s are plotted. Most of the data is well within specification. In a few situations we found a flaw with the self-alignment software that allowed reference to an incorrect value