A number of things come together in this composite SBB model:

• On the one hand, the email ABB is completed by an Email component in the application layer.
• Secondly, the ABB emails are completed by a technical function and service within the infrastructural ABB and SBB.
• The example shows how a service connects the layers.
• The model includes a secondary element as an example of an interface based on a mail protocol.

Diagram in reading mode