Testing the bounds of your lockdown arrangements
One of my clients has an access control system that covers all of exterior doors and several interior doors. Security can use an emergency shutdown button if the facility needed to be locked down.
This approach is absolutely in keeping with what I would consider a best practice, particularly because it allows flexibility in where and how seamlessly you can establish a secure perimeter for the organization.
The challenge then becomes whether someone either accidentally or purposely breaches the perimeter. The organization needs to identify what resources are required to monitor all ingress and egress points, including but no limited to door alarms in certain locations.
If your facility has a similar arrangement, the next time you conduct an exercise that involves a lockdown, game plan some attempted intrusion events as a wild card and see where the potential gaps are. Pick a “suspect” to help who looks normal, but is inventive in trying to get in or out — no point in not making the exercise interesting.



