The repairs of the repairers are generally paid. Soviet experience still: if repairers pay off, they will repair so that it hangs on the stoves and breaks in two days, and it would be possible to repair on the stoves again. If you pay a salary and a premium for safety, the technology suddenly begins to figured like a clock, and the repairman himself sits half a day in combat readiness, and half a day pursues prevention, because it is not in his interest to have as many facts of repair as possible, but as few facts of breakdown as possible.