Imagine you want to implement a vacation-booking service 
  as part of an enterprise system. The first step is to 
  remove any reference to computers or modern technology. 
  This will allow you to concentrate on the business 
  objectives of the service, without getting sidetracked by 
  technological considerations. In other words, it enables 
  you to separate the “what” from the “how.”

That's pretty great advice.