Implementing Domain-Driven Design

Make Sure You Need a Service

Don’t lean too heavily toward modeling a domain concept as a Service. Do so only if the circumstances fit. If we aren’t careful, we might start to treat Services as our modeling “silver bullet.” Using Services overzealously will usually result in the negative consequences of creating an Anemic Domain Model [Fowler, Anemic], where all the domain logic resides in Services rather than mostly spread across Entities and Value Objects. The following analysis shows the importance of thinking carefully about the tactics you should employ for each modeling situation. Following this guidance should help you make good decisions about whether or not to model a Service.

Let’s investigate an example of recognizing the need to ...