DMN requirement elements
The decision requirement diagram sits above the tables and shows structure: which decisions depend on which other decisions, what input data they need, and which knowledge sources govern them.
It is the map. The tables are the detail.
#When it matters
Decisions built from several sub-decisions.
Governance work, where the authority behind a rule matters.
#The symbols
Symbol | Means |
|---|---|
Decision | Rectangle. Produces an output from inputs. |
Input data | Rounded rectangle with flat ends. Data supplied from outside. |
Business knowledge model | Rectangle with clipped corners. Reusable logic. |
Knowledge source | Wavy-bottomed shape. The authority: a policy, a regulation, a person. |
Information requirement | Solid arrow. Data flowing into a decision. |
Authority requirement | Dashed arrow. A knowledge source governing a decision. |
#A few things that catch people out
Knowledge sources are how you record that a rule comes from a specific regulation. Auditors ask.
Information requirements are solid; authority requirements are dashed. They are not interchangeable.
Draw the requirement diagram first. It shows how many tables you actually need.
#Related
Pick the hit policy on purpose.
