Answer to sTEm–at-Work Puzzle #37: Machine System Performance

The Problem
A Certified Process Technician, CPT, has reviewed the data taken from Run Charts for two Machine Systems, System #425 and System # 638, to assess their performance and determine if either, or both system’s preventive maintenance schedules should be interrupted with an unscheduled maintenance check. The plots summarize system performance by presenting daily average radius measurements performed by the Tech. After studying this information the Tech has made a decision. This puzzle is an open-ended opportunity to present, discuss, and manipulate Run Charts. 

 The graph presents agglomerate measurement data, but does not include any performance limit expectations. A discussion of a more formal presentation of Run Chart information is certainly an easy next step for this puzzle. However, even with the graphic limitations in the plots provided it is clear that one of the systems is not performing as expected.

The technician decided that both systems are operating as expected. NO