Chapter 2. UML Essentials
All models are wrong, but some models are useful.
To design a system—any system in any scientific field—you first need to create an abstraction of it. An abstraction is essentially a model that provides a conceptual representation of the system in terms of views, structure, behavior, participating entities, and processes.
A model exists to be shared among the stakeholders of the system, including developers, architects, owners, and customers. Stakeholders should be able to understand the model in order to provide feedback, spot wrong assumptions, and suggest improvements. To share a model, though, you need to express it in a formal way using a common, and possibly broadly accepted, notation. For this, ...