Be prepared to ask five whys about a problem.
Example... A pump burned out - why? There where metal filings in the bearings - why? The filter screen wan't on the filter - why? Because it fell off and was on the bottom of the coolant basin - why? The maintenance man didn't put a lock nut on the filter. Why?... and, bingo... there's the real problem!
Five "whys" lets you prevent recurrences of a problem. One why lets you take emergency - and temporary - corrective measures.
Basic Management Philosphy Handbook for Toyota for its joint venture with General Motors.