Imagine you're a huge construction company. You've got trucks to build your massive skyscrapers. You can use dumper trucks to carry your heavy construction materials, but when the road's slippery, it's difficult to get your trucks down the hills. You can use a backhoe loader to cut out a path, but the problem is that they need to be cut out in specific places so they won't break the road.

Now you've got to get your trucks to work so they won't break.

You've got to drive a lot of heavy machines to excavate.