Have a look at following two references from CIO magazine.
They support my arguments about the importance of using scoping techniques like the Context Diagram and the B5 technique. We should use these techniques, of course as part of understanding the “as is” business, but more importantly as a way of describing the business’s or system’s goals. this often can lead to the uncovering of additional opportunities to improve the value of the business.
The key factor when scoping and when understanding the “as is” (I prefer the term “what are we trying to achieve?” over the term “as is”) is to focus on the what and not on the how. Too early a focus on the how is as bad as committing the crime of premature design.
Posted by John Watson