Key takeaways
- Remember Name, Statement, Rationale, and Implications.
- Rationale connects a principle to business value.
- Quality must also be assessed across the complete set of principles.
A rule with consequences
A principle expresses enduring direction used to guide decisions. It contains a Name, Statement, Rationale, and Implications. Its name should be clear, its statement understandable, its rationale connected to business needs, and its implications concrete enough to inform choices, costs, and responsibilities. A slogan without consequences cannot support a trade-off.
Architecture principles should align with enterprise principles. Their development considers mission, strategy, initiatives, external constraints, and the technology environment. Architects and stakeholders contribute to formulation; approval follows the appropriate governance arrangements.
Test the complete set
A set of principles should be understandable, robust, complete, consistent, and stable. It covers important decisions, works across different situations, and avoids unmanaged contradictions. When two principles conflict, priorities and trade-off arrangements should be explicit. Stability does not prohibit a justified change when the context changes.
- Original example: prefer documented interfaces to support service evolution.
- Explain documentation costs and maintenance responsibilities.
- Ensure that any exceptions are governed rather than silently ignored.
TERMS TO KNOW
The terms, in context.
- Architecture Principle
- Enduring rule guiding architecture decisions.
- Implications
- Practical consequences of following a principle.