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2. The Structure and Semantics of Models

If models are the foundation of MDA, then structure (organization) and semantics (meaning) are the bedrock.

From Whiteboard Sketches to Durable Knowledge​

Informal sketches are useful for brainstorming, but they lack durability. A photo of a whiteboard is just a static image. MDA transforms these concepts into semantic data—the underlying facts behind the pictures.

Once captured as semantic data, you can:

  • Query and analyze the architecture.
  • Repurpose data for different views (e.g., a security view vs. a functional view).
  • Automatically derive code or tests.
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Semantics refers to the precise meaning defined by MDA standards. This ensures that both humans and tools interpret the model the same way.

The Domain Subject Area​

Models always describe a specific Domain—the slice of reality or business logic we are addressing.

  • Broad Domains: Healthcare, Telecommunications, Finance.
  • Specific Domains: A hospital's patient intake process or a specific warehouse's inventory logic.

Viewpoints and Views​

Stakeholders require different perspectives on the same domain.

  • Viewpoint: The set of rules or "lens" used to look at the system (e.g., a Security Viewpoint).
  • View: The actual representation created using that lens.

Separation of Concerns​

Separating these views allows specialists (e.g., security experts and database architects) to work in parallel without cluttering each other's workspaces.