Diamonds

Diamonds are formed under high pressure over long periods of time. If you want to turn your employees from lazy slackers (lumps of coal) into hard-working diamonds, you've got to apply sustained pressure. Constant pressuring with deadlines, heavy workloads, multiple daily progress reports, meetings questioning everything they're doing, etc. is what is needed. Hard work never killed anyone, except in Japan, but even that is debatable. The life of the PHB is tough; applying the pressure to mold your employees takes some effort.