Barb von Halle and Larry Goldberg had an interesting article titled Use Cases and Business Rules – can they work together over on Modern Analyst. In the article they discuss the role of the Decision Model and business rules in use cases.
They make some good points and I have a simple summary I would like to share for those who want to capture use cases and business rules during requirements gathering:
- Look for decisions in your use cases (see this post by a friend of mine on finding decision points and my follow-up on types of decisions).
- Make them explicit, describe them, understand what question/answer is at the heart of the decision (“Is this customer eligible?”,”What’s the right risk adjusted price for this product for this customer?”)
- Track but don’t embed the rules that drive them so you can trace from a use case to a decision to the rules that describe it
- Don’t list rules in the use case steps or in the description of the use case – let the decisions act as a layer of indirection
- Remember that business rules can be reused across decisions and that decisions can be reused across use cases.
You might also find this technique for decomposing decisions to be helpful.
I also wrote an article on the same site on the role of Decision Management in requirements.
