page_title: Fundamental modeling concepts
section_title: Compositional Structure Diagram
hierarchical_section_title: Fundamental modeling concepts / Diagram Types / Compositional Structure Diagram
caption_attribution_description: FMC Block Diagram (Example)
context_page_description: Fundamental modeling concepts provide a framework to describe software-intensive systems. It strongly emphasizes the communication about software-intensive systems by using a semi-formal graphical notation that can easily be understood.
context_section_description: Compositional structure diagrams depict the static structure of a system, and the relationships between system components. System components can be active or passive. Agents are active system components. They perform activities in the system. Storages and channels are passive components which store or transmit information.
  The image to the right is an example of a compositional structure diagram. It contains the agents Order Processor, Supplier Manager, Supplier, Online Shop and an unnamed human agent. Agents are represented by rectangles. The dots and the shadow of the agent Supplier indicate that this agent has multiple instances, i.e. the Supplier Manager communicates with one or many suppliers. The so-called human agent represents a user interacting with the system.
  The diagram contains the storages Orders, Purchase Order and Product Catalog. Storages are represented by curved shapes. Agents can read from storages, write to storages or modify the content of storages. The directions of the arrows indicate which operation is performed by an agent. In the diagram, the Supplier Manager can modify the content of the Product Catalog, whereas the Order Processor can only read the content of the Product Catalog.
  Agents communicate via channels. The direction of information flow is either indicated by arrows (not shown in the picture), by a request-response-symbol (e.g. between Supplier Manager and Supplier) or omitted (e.g. between Order Processor and Supplier Manager).
caption: Example of FMC Compositional Structure Diagram
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