Key takeaways
- Choose the detail that supports the decision.
- Trace concrete choices back to their purpose.
- Do not confuse abstraction levels, architecture domains, and ADM phases.
Four different questions
The contextual level explains why change is needed, which stakeholders are involved, and which boundaries apply. The conceptual level identifies what needs to exist: essential capabilities, services, or information, without immediately choosing an implementation. The logical level describes how elements should be organized and connected, with enough precision to reason about their behavior. The physical level identifies the concrete means used to realize that organization.
These levels help avoid discussing a product before the objective is clear. For a notification service, separating communication needs, the expected service, routing rules, and the selected platform makes it possible to compare alternative solutions.
Match detail to the audience
Executives deciding on an investment need different detail from an implementation team. Descriptions must nevertheless remain consistent: a physical choice should be traceable to expected logical behavior and a business justification. These abstraction levels are not additional ADM phases, and they do not require four separate documents for every element.
- Why: context and justification.
- What: conceptual intent.
- How: logical organization.
- With what: physical realization.
TERMS TO KNOW
The terms, in context.
- Logical
- Description of intended organization without dependence on a particular product.
- Physical
- Description of concrete implementation means and components.