One way to think about the problem is that the the business people on the design team have left the project before you have enough working software to see how users react to it.

     The business people are your best assets for judging the usability of the software.

     The “Collaboration Barrier” is the moment coding starts, when the business people lose most of their input to the project.

Business Input Into What the Product Is

Goes Way Down When Coding Begins