The answer to sTEm Puzzle #37 suggested that although the data plotted below was acquired from a Run Chart for each system, more information would be provided if the plots were actually Run Charts. However, because of the Certified Process Technician’s knowledge and training, a decision about expected system performance could still be made. Thus, it is clear to the CPT working for the marine engine manufacturer that it is not true that both of these machine systems are operating correctly (see puzzle #36).  However, it is also clear to this Tech that only one of the systems, either System #425 or System # 638, was not performing as expected.

The Tech correctly identified the system that was not operating properly and submitted a request for an unscheduled maintenance shutdown to trouble shoot and repair that system.