The Business Need
There is a famous anecdote about NASA invesing millions of dollars to create a pen that worked in space, resulting in the Fisher Space Pen. The Russian cosmonauts used a pencil. The point is that the 'want' was a pen, the 'need' was a 'writing implement'. The story may be apocryphal, but it highlights that asking 'why?' may uncover latent value in the specification or scope of work.
Other videos that address the business need include War Story #10