As promised this post is about High reliability organizations. If you haven’t read the latest post about natural accident theory (NAT), we recommend you to, by following this link

Around the same time Perrow articulated his NAT (natural accident theory), another stream of research emerged. Sholars from the Berkely campus of the University of California came together to study how organizations that operate complex, manage to remain accident-free for a longer time. This group and other scholar’s latter became what we know as HRO.

High reliability organizations operate in complex, high-hazard domains, for extended periods without serios accidents or catastrophic failure.  

Just like in the NAT, HRP are related to the two dimensions; interactive complexity and loose/tight coupling – which Perrow claimed together determine a system’s susceptibility to accidents.
Interactive complexity refers to the presence of unfamiliar or unplanned and unexpected sequences of events in a system that are either not visible or not immediately comprehensible. A tightly coupled system is one that is highly interdependent: Each part of the system is tightly linked to many other parts and therefore a change in one part can rapidly affect the status of other parts. Tightly coupled systems respond quickly to perturbations, but this response may be disastrous. Loosely coupled or decoupled systems have fewer or less tight links between parts and therefore can absorb failures or unplanned behavior without destabilization.  An HRO is hypercomplecity – extreme variety of components, system, and levels, combined by a really tight coupling, meaning a reciprocal interdependence across many units and levels.

Why reliability?

Although HRT scholars have abandoned attempts to explicitly define reliability, they appear to agree that reliability is the ability to maintain and execute error-free operations. 

HRO scholars report that HRO emphasis the following conditions as being necessary, but not sufficient, for ensuring reliability: a strategic prioritization of safety, careful attention to design and procedures, a limited degree of trial-and-error learning, redundancy, decentralized decision making, continuous training often through simulation, and strong cultures that encourage vigilance and responsiveness to potential accidents.

Why is this important?

It is important to recognize that standardization is necessary but not sufficient for achieving resilient and reliable health care systems. High reliability is an ongoing process or an organizational frame of mind, not a specific structure. Examples of such organizations could be health care organizations aiming to become highly reliable in their report of practice. Other examples include Air traffic control system, nuclear power plant and NASA. In each case, even a minor error could have catastrophic consequences.

Your organization

Even though your organization might not hold lives in its hands, all organizations still face risks to profits, customer satisfaction, and reputation. The behaviors of HROs can be very instructive for those trying to figure out how to error-proof processes, avoid surprises, and deliver the desired outcome every single time.


Shrivastava, S., Sonpar, K. &Pazzaglia F. (2009) ”Normal accident theory versus High reliability theory: a resolution and call for an open systems view of accidents”, find it here

Marais, K., Dulac, N. & Leveson, N.:” Beyond normal accidents and high reliability organizations: The need for an alternative approach to safety in Complex systems”, MIT find it here

About the author

Julie Hviid



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