sentence1: A typical turnkey 500 MWe unit FGD system retrofit requires 380,000=man-hours, or approximately 200 person-years, of which 20 percent, or 72,000 man-hours, are dedicated to engineering and project management,3 and roughly 40 percent of man-hours are for boilermakers.
sentence2: And FGD system requires more man hours than any other unit.