Rationale
ExplanationInformative
Rationale
Why the standards exist, which costs they avoid, and where their boundaries and trade-offs lie.
Open a rationale page when you need to understand or challenge a rule. The normative statement remains in its owning standard or artefact; these pages explain why it exists and where it stops applying.
Product design
| Topic | Explains |
|---|---|
| Open systems | Why variable values belong in the model now while administration can remain deferrable |
| Configurability boundary | How configurable values remain bounded by fixed invariants |
| Eight principles | The cross-project design principles and the cost each avoids |
Decision quality
| Topic | Explains |
|---|---|
| Four lenses | Why structural decisions are tested as architecture, delivery, implementation and interface |
| Naming | Why established domain vocabulary beats invented terminology |
| Red flags | Which sentences reveal a rigid model, forked authority or bypassed gate |
Architecture
Hexagonal architecture carries both the standing rules and the trade-off against a layered structure.