Implementing Domain-Driven Design

Don’t Trust Every Use Case

Business analysts play an important role in delivering use case specifications. Much work goes into a large and detailed specification, and it will affect many of our design decisions. Yet, we mustn’t forget that use cases derived in this way don’t carry the perspective of the domain experts and developers of our close-knit modeling team. We still must reconcile each use case with our current model and design, including our decisions about Aggregates. A common issue that arises is a particular use case that calls for the modification of multiple Aggregate instances. In such a case we must determine whether the specified large user goal is spread across multiple persistence transactions, or if it occurs within just one. ...