The best resource to provide credible information on the recommended components of a mass notification system can be found in the United States Department of Defense Unified Facilities Criteria (UFC), UFC 4-021-01, published in December 2002 and still in effect today. These published criteria, following the 9-11 tragedy, provide in pertinent part: “Mass notification is the capability to provide real-time information to all building occupants or personnel in the immediate vicinity of a building during emergency situations. To reduce the risk of mass casualties, there must be a timely means to notify building occupants of threats and what should be done in response to those threats. Pre-recorded and live voice emergency messages are required by this UFC to provide this capability”.

It is clear from the criteria contained in DOD, UFC 4-021-01 that an appropriate and capable Mass Notification System must have the capability to instantly broadcast voice instructions that will appraise people what has occurred and instruct of what to do. The instructions should be customized for each building and zone to match its unique evacuation plan. Other instant alerts such as public area LED displays and strobe lights are important as well for the hearing impaired. E-mail text messaging and phone message distribution alerts can be used in non-critical situations or as a secondary option due to their relatively slow notification process, lack of ability to notify all intended message recipients, and the tendency of communication lines to fail due to an overload during an emergency.