The Rational Edge -- March 2001 -- Iteration-Specific Requirements: More Control Where You Really Need It The BAR technique gives the entire project team extra control in situations where it's really needed for the small cost of an extra requirement type and some up-front planning:
>For the software architect, it provides better scope control for iteration content.
>For the testing and development teams, it provides better communication about what will be delivered.
>For project managers, it affords more insight into changing requirements via metrics that differentiate between changes to user requirements (use-cases), and changes that indicate architectural alterations (BARs).
>Politically, another advantage of the BAR technique is that it provides a comfort factor for managers who are hesitant about moving to an iterative process. It gives them more visibility into the "hedged bets" that software architects must make concerning technology decisions in early iterations as well as a way to measure their outcomes.