Managing complexity - how to build a framework for managing BA?

One of the main challenges in IT projects is managing complexity. Typical projects involve many stakeholders, dozens of requirements, artifacts evolved from requirements... There may be various relationships between artifacts, some artifacts are derived from other ones, some stakeholders may require specific artifacts to be delivered... Some stakeholders have special information requirements.

BA artifacts like goals, needs and requirements define the scope and shape of the final solution. Their importance cannot be questioned. The only remaining question is how to manage the information to be able to control the scope and progress of work, to communicate effectively with stakeholders and "see the whole"?