Knowing when, where and how your users connect and communicate through out their job duties is essential in understanding where their struggles might be.
Creating a high level overview with every touch point, communication or handoff simplifies this process and creates a much clearer picture.
Understanding a timeframe from which your user gets from point A to point B, and every touchpoint in between, will allow you to explore better solutions and ideas. This also gives the stakeholders a better idea of what is REALLY happening today. What the stakeholders THINK they know and what the users are ACTUALLY doing, in most cases, is not the same.