Field technician: Where does the grey wire from terminal 21 go?
Engineer: Grey? That wire should be light blue.
Field technician: All the wires I see are grey.
This is what happens when the talented but willful production team takes engineering directives as suggestions. Decisions regarding component selection are informed by specifications, regulations, physical laws, and personal preference. Regardless of how a decision was arrived at (fortune cookies, dice rolling, asking the janitor, etc.), it is not the place of production to second-guess engineering. If it was, then they would be the ones in a windowless office under flickering fluorescents, surrounded by productivity-increasing bland grey furnishings.
I am not talking about problems reported back to engineering for correction. I am talking about laborers thinking they will use a solenoid in place of the one you specified, because it looks similar and has the same voltage rating, and then not telling anybody.
Excuses like "I ran out of blue wire," "It's almost identical," and my favorite, "That's not how we used to do it," are not valid excuses. I can't even think of a valid excuse. In this particular case, a multimillion-dollar fire suppression system was to be installed throughout a manufacturing facility. This location routinely bursts into flames, they use kerosene as a lubricant. Fire breaks out, CO2 floods the area, workers have just enough time to escape certain suffocation. The control panels for this facility were being repaired and upgraded, when some questions arose. As they gave the opening exchange, above, they had replaced control panels wiring with some grey wire that looked "like the same stuff." After an argument over the wire, the engineer's demands won out. The project was on hold until the proper wire was obtained.
How do we assist the field tech or customer when documentation does not match the physical design in the field? An adulterated design which may later require the ministrations of a technician because production took liberties during construction.
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