Understanding Application Communication Diagrams, UML/BPMN EAP Profile, and Archimate

The purpose of the Application Communication Diagram is to describe all models and mappings related to communication between applications in the meta‑model entities. It shows the interfaces between application components and components; where appropriate, interfaces can be associated with data entities, and applications can be linked to business services. Communication should be logical and display only mediation technologies relevant to the architecture.

Tip: Use application components to present a SOA‑oriented architecture as much as possible. Different types of application components can be structured into layers, mainly GUI (interactive), process, and entity components. Legacy systems or external applications may result in a hybrid architecture; "Application" or "Database" components can be used and mixed with SOA service components. Application components are connected by required or provided services, which are linked by connectors. Provided/required services are typed by IS service types usually modeled elsewhere.

The diagram may represent an existing application map or a logical architecture of a future scenario, encouraging the use of SOA‑type architecture based on service‑oriented application components. In hybrid architectures, a combination of non‑SOA applications, repositories, and new SOA parts can be shown.

In an SOA‑oriented architecture, it is recommended to structure service application components according to their nature and level: components dedicated to interaction (GUI, WEB), components dedicated to process execution, and the most stable entity components.

Components interconnect via their required and provided services, which are linked by connectors. These services are typed by IS service models defined elsewhere. Service operations transfer data (parameters), whose types are also modeled as "messages".

UML/BPMN EAP Profile

Interactive Application Component: Represents top‑level components that manage interaction with external elements, typically a GUI such as a web interface.

Entity Application Component: Derived from business entities, responsible for managing access to and integrity of those entities.

Process Application Component: Handles business process execution and orchestrates task flows.

System Federation: Coarse‑grained component that assembles systems to work together, e.g., cross‑company collaborations.

Utility Component: Frequently reused components, often off‑the‑shelf.

Database Application Component: Represents a repository; in pure SOA it should not appear, but it is useful for legacy analysis or technical architecture.

Application: Corresponds to legacy applications, commercial products, or assembled groups of components.

Provided Service: Accesses an application component via a service it offers.

Required Service: A service that a component needs, which must be connected to a provided service of another component.

Connector: Links provided or required services between component instances.

Information Flow: Defines any type of flow of information (business entities, events, products, informal data, etc.) between enterprise activity entities.

Flow Link: Connects data (e.g., business entities, events, products) with activity elements (e.g., business processes, services).

External Participant: Participants outside the enterprise.

Consumption Link: Shows a participant consuming an IS element (service, operation, application component).

Archimate

Architecture is layered: interaction components (site) at the top, process components in the middle, and entity components at the bottom.

Source: https://architect.pub/togaf-modeling-application-communication-diagrams