BPM Institute has a nice Case Study: Business Rules and Requirements Management at the IRS about the IRS' piloting of a new methodology for analyzing, documenting, and managing business rules in conjunction with requirements for system design. Has some good discussion of the differences between business rules and requirements as well as their similarities about which I have blogged before:
- Techniques for gathering rules and requirements
- Digging yourself out of the requirements tarpit
- Building better requirements - is it a false hope
And I reviewed a great book on use cases you might enjoy also.