That's usually done in manufacturing when I worked in that - you can shut down whole production lines for big maintenance, plan delivery (demand is seasonal for

That's usually done in manufacturing when I worked in that - you can shut down whole production lines for big maintenance, plan delivery (demand is seasonal for eg.) and optimize workers required (eg you are running 3 shifts 24 hours you need 3 crews - having flexible vacation and working all year means you need more backup guys than if you just shut down for x days and send everyone off). This sucks for workers because you don't have flexibility on when you want to use your vacation.