A study was done a while ago comparing hospitals that use checklists and those that don't.

Most doctors went into the study saying "I don't need a checklist."

Those that went along (grudgingly, usually) with the checklist idea found that their error rates were reduced to a statistically significant degree.

Hospitals that instituted an institution-wide checklist policy reduced their costs resulting from malpractice suits, insurance, etc., by an average of 20%.

Worth thinking about for the mechanics here who trust their instincts implicitly.