Une Business Logic simple peut être implémentée avec le Transaction Script Pattern par exemple. Mais lorsqu’elle devient complexe il nécessaire d’implémenter plusieurs patrons autour de la notion de Domain Model.
In his book, Evans presents a set of patterns aimed at tightly relating the code to the underlying model of the business domain: aggregate, value objects, repositories, and others. These patterns closely follow where Fowler left off in his book and resemble an effective set of tools for implementing the domain model pattern.