- The top layer captures the interactions between different business domains, or to take an APQC classification terminology for level 3 decomposition "processes".
- The next layer is workflow between different actor belonging to the same business subdomain .
- One layer below captures the interactions of a single human actor with the system for a particular task of the above workflow.
- The bottom layer addresses the matchmaking usually implemented in ESBs, to expose the appropriate services using adaptation or combination of existing interfaces.
To differentiate Service Oriented Architecture and Event Driven Architecture the classical gang of four work on Design Patterns can be used as described by the following picture.