Assign a role to each recovery phase
Synthetic recovery starts 09:00. Preparation needs operator O for 12 minutes; then verification needs verifier V for 15; then release needs O for 5. O is available 09:00–09:20 and 09:40–10:00; V09:12–09:35. Phases are sequential and cannot be split. Deadline 09:40 requires release complete, not just verification. A phase may end at its role window boundary.
| Phase | Role/duration | Earliest covered execution |
|---|---|---|
| Preparation | O /12 min | 09:00–09:12 |
| Verification | V /15 min | 09:12–09:27 |
| Release | O /5 min | 09:40–09:45 |
Advance only through covered phases
- Finish preparation inside O coverage
- Verify only after preparation
- Wait for a covered O release phase
Verification success cannot silently authorise release without its supplied role and phase.
What state is reachable by 09:40, and when can release finish?
Show the worked answer
Data can be verified at 09:27, but release finishes no earlier than 09:45, five minutes late. The 13-minute gap 09:27–09:40 has no O coverage for release. O and V need not be simultaneously present because the supplied phases use different roles.
Name the reached recovery state
| Case | Decision | Reason |
|---|---|---|
| Call 09:27 service released | Reject state claim | Release phase unfinished |
| Release 09:40–09:45 | Covered but late | Deadline 09:40 |
The scheduling output is a verified-data frontier plus a pending release phase. A revised operator window must support the full five-minute release before the deadline to change that decision.