DDD — Notes from the big blue book. Part 5

Chapter 9

• To find implicit concepts
• be aware of hints in the design
• search them out
• listen to language used and learn
• Scrutinise awkwardness of design
• Scrutinise code that does awkward things and is hard to explain
• Domain experts may be inconsistent — this may indicate an implicit concept
• Make constraints explicit
• Look at analysis models/patterns
• Ideally do not want to make procedures a part of the domain model — unless they are spoken about

Chapter 10

• State post conditions of operations and invariants of classes and aggregates — ** maybe as unit test? **
• Models are awkward because they are missing pieces — successive refactorings lead to conceptual contours which clarify the model
• Decompose design elements consistently with the domain
• A requirement that forces extensive change is a sign that the model does not fit
• ** Closure of operations **
• Carve off sub-domains