Business Activity is absolutely central to how a business operates: supporting what a business does by delivering on business capability.
It is imperative that the business has a real understanding of
- how activities are structured;
- what information they require;
- what technology sets they leverage;
- what events trigger them and are in turn triggered by them
- how they relate to other activities and
- what processes consume them.
Understanding how the business operates at this level provides the opportunity to engage in Business Process Improvement or Business Process Re-engineering.
Detailed knowledge of how any given activity works within the full business context ensures that the impact of change can be assessed. With knowledge comes the ability to
- Refine the tasks that sit within in the activity
- Re-sequence activities within a process
- Redefine information flows and
- modify the behaviour of triggering events.
To effectively manage activities within the business, the processes that contain them should be fully documented.
Using an appropriate modelling tool can also allow the business to readily navigate through the processes, gaining an end-to-end perspective of business operations. This gives the additional benefit of being able to highlight bottlenecks and/or barriers within the business.
Identification can subsequently lead to their removal and thus to increased efficiency.
The Knowledge Economy 
Great post..