Suppose a particular extruder goes down due to a heating element failure. What’s the response? It should consist of known, documented steps that everyone follows the same way every time.
Suppose, instead of doing a standard diagnostic that checks for a short list of conditions, one technician does a complete system check by following the manual. Another does this check from memory (forgetting some things), and a third just wings it. A fourth doesn’t know what to do and asks another technician.
The next steps are similarly all over the place. One technician removes just the heating element, another takes the heating barrel apart, another technician does X, and another Y. This variance in methods means the total repair time varies from 40 min. to 180 min. However, one technician follows a written standard response. He never requires more than 25 min. to complete the repair.
Standard responses do the planning “offline” instead of when the equipment is down. Develop one for every failure mode of critical equipment.