Below is something that was just posted on a listserv I belong to. The writer is a fellow with experience in ERP implementations and lots of opinions. I think his comparisons are funny, and well worth thinking about!
It's all about Elephants...
Like elephants, ERP projects are so large that any one person, examining them, could rightly claim that they are like snakes, like trees, like walls, or like hard pointy things.
Like elephants, ERP projects are too large to eat at one sitting. You need to make elephant hamburgers out of them first.
Like elephants, they can inadvertently squash you if you are not careful.
Like elephants, they have considerable inertia, and are difficult to get to change direction.
Like elephants, they can startle at the oddest things, and go off at a random tangent you neither want, need, nor like.
Nic Harvard