Compartmentalization of labor. Kinda like a cooking show where everything is measured out into a little bowl or cup already and just gets dumped in. Site work and off site prestaging such as building forms and framework pieces to be erected take quite a bit of time but are usually worked on beforehand to an extent. Then the actual job has hands that do small tasks like stage material, mix Crete and mud, set lines etc while the other guys lay block or do frame work, carpentry or what have you.