Simon Brown’s 4C model - Intro

This learning hour introduces the basic ideas in The C4 model for visualising software architecture

Learning Goals

Session Outline

Connect: What are software architecture diagrams for?

Think about what you already know about software architecture diagrams. Write three facts on postits. Be ready to state them when asked. (Think it then ink it)

When everyone has written something, pair them up and have them share their facts to one another. You can continue working in the same pairs in the rest of the session.

Concrete: analyze Instavoiced

Working in pairs, read the description of the Instavoiced system.

Use paper or a whiteboard.

Concept: 4C model

The front page of the The C4 model for visualising software architecture website explains these concepts. Present them in your own way.


Continuing with the same Instavoiced system, start over on your diagrams. Draw a Context diagram. Use paper or a whiteboard.


Each pair posts their original and new diagrams in a place where everyone can see them. Walk around and look at everyone’s diagrams. Each person should note for themselves what is important to include or not include in a Context diagram.