2 use cases: 2 still miss something, and 1 things on the map have no use case.
| Use case | Concept Logical payment | Concept Order | Concept Processor confirmation | Concept Refund |
|---|---|---|---|---|
| Pay for the €100 lamp 1 missing | W | R | W | T |
| Refund the unavailable lamp 1 missing | R | T | W | W |
| Covered by | 2 | 2 | 2 | 2 |
W Writes to it or sends it work R Reads from it T Passes a part it lives in