Entry on Every Attempt
Expectation. The building shall grant entry to every credentialed person at every designated entry point, on every attempt, regardless of time of day, network condition, or device state.
Required.
- Entry succeeds on every attempt when a valid credential is presented.
- Entry functions during network interruptions.
- A system change — software update, firmware upgrade, configuration change — does not invalidate existing credentials or interrupt entry.
- The resident receives advance notice of impending entry point degradation before that degradation prevents entry.
Recommended.
- System changes are applied without any period of entry unavailability.
In practice.
The building's internet connection drops at 11 PM. A resident returning home presents their credential at the lobby, elevator, and unit door. Every entry point opens. The resident does not know the network is down because the experience is identical.
The access system receives a software update overnight. The next morning, every resident's credential works exactly as it did the day before. No one is asked to re-enroll, re-download, or re-authenticate.
A firmware update is scheduled for the parking gate controller. Residents receive a notification the day before: parking gate update tonight between 2 and 4 AM — use lobby entry if arriving during this window. At 6 AM, the gate operates normally.
Failure modes.
Expiring cache. The system stores credentials locally for network interruptions, but the local store expires after a fixed period. An overnight outage outlasts the cache. Residents who left the evening before re-enter without issue; residents who return the next afternoon are denied.
Degraded-mode reduction. During a partial system failure, the system falls back to a reduced state that grants lobby access but silently drops elevator authorization. The resident enters the building but cannot reach their floor. The system considers itself operational.
Update-triggered re-enrollment. A firmware update completes successfully. The system functions normally — for residents who open the app and accept a new authentication prompt. Residents who do not open the app before their next entry are denied. The update did not invalidate credentials in theory; in practice, it broke entry for anyone who did not perform a manual step.
Test.
- Present a valid credential at each designated entry point. Confirm: opens on the first attempt.
- Disable network connectivity. Present a valid credential at each designated entry point. Confirm: entry succeeds at every point.
- Disable network connectivity for a duration exceeding the system's local credential cache period, if one exists. Present a valid credential. Confirm: entry still succeeds.
- Apply a system update. Present existing credentials without any manual re-authentication. Confirm: all credentials remain functional.