Why not add to the game factories with machines. On which it was necessary to process pipes for manufacturing, to stamp sleeves and much more. You can find a lot of plant application. But not everything is so simple. Near the plant would be full of zombies, which did not allow you to go to it. To make it in the factory, you must first clear it. It was necessary to provide protection, turrets, stakes, strong walls around the plant. And almost every day came the hordes of zombies, to again "settle down" in the factory. You can also add random NPCs on the cards, and send them to the factory, so that they work in exchange for protection and food.