Most hospitals have utility failure procedures for major utility systems or equipment.  However, existing utility failure procedures may have room for improvement, particularly in how they deal with common-mode failure potential within their utility systems and equipment.  Reliability professionals generally consider that multiple failures, including failures in otherwise redundant equipment, attributable to a common cause are common mode failures.

A recent airport power failure occurred because an electrical equipment fire damaged nearby redundant circuit cables and switching mechanisms according to that airport’s statement.  Based upon the statement, it appears that a common-mode failure aggravated the situation.

This situation is not uncommon.  Many organizations, including many hospitals, have conditions where one incident can result in multiple outages.

Robust utility failure procedures should consider not only equipment capacity redundancies and commonalities, but also redundancies and commonalities in location, distribution, and necessary functions such as power and controls.

The list below provides typical examples of such situations in health care facilities.

Examples of single failure points that should be considered within utility failure procedures are listed below.  These situations and other similar issues are not uncommon because of capital funding restrictions.

• A common fuel oil header serving multiple fuel oil storage tanks
• A dual fuel oil pump skid with one power source and one control panel
• Multiple generators whose necessary auxiliary equipment is all powered by one power source
• Backup boiler controls that receive power from the same power source as the primary boiler controls
• Any redundant utility system equipment that is connected to the same distribution pathways
• Redundant system components that are located within the same space
• A single natural gas supply line serving redundant boilers
• A single high-pressure steam line that distributes steam from all available boilers
• A building automation system and/or air temperature control system that controls redundant equipment or redundant systems
• A common chilled water pipe (primary or secondary) that serves redundant chillers
• A common cooling tower that serves or header that serves redundant chillers
• An electrical switchboard that provides power to redundant components
• An automatic transfer switch that provides power to redundant components
• A single medical gas main distribution line that serves multiple medical gas risers

Within CMS Survey & Certification Letter 17-29 Appendix Z, Emergency Preparedness Final Rule Interpretive Guidelines and Survey Procedures, CMS defines the required All-Hazards Approach as:

“All-Hazards Approach: An all-hazards approach is an integrated approach to emergency preparedness that focuses on identifying hazards and developing emergency preparedness capacities and capabilities that can address those as well as a wide spectrum of emergencies or disasters. This approach includes preparedness for natural, man-made, and or facility emergencies that may include but is not limited to: care-related emergencies; equipment and power failures; interruptions in communications, including cyber-attacks; loss of a portion or all of a facility; and, interruptions in the normal supply of essentials, such as water and food. All facilities must develop an all-hazards emergency preparedness program and plan.”

It appears that including common-mode failure potential would be a wise approach to include within healthcare facility utility failure emergency planning and utility failure procedures.

NFPA Disclaimer: Although the author is a primary voting member and was the 10-year Chairman of the NFPA Technical Committee on Emergency Power Supplies, which is responsible for NFPA 110 and 111, the views and opinions expressed in this message are purely those of the author and shall not be considered the official position of NFPA or any of its Technical Committees and shall not be considered to be, nor be relied upon as, a Formal Interpretation. Readers are encouraged to refer to the entire texts of all referenced documents.  Interested parties can review copies of NFPA 110 at www.nfpa.org/110.

Questions related to this article may be directed to the author, David Stymiest, PE, CHFM, CHSP, FASHE, at DStymiest@ssr-inc.com.