This is the third installment of lessons from systems thinkers I admire. Years ago, I had the privilege of listening to and learning from Prof. Russell Ackoff for a day and a half. At the time, he was at the end of his long, illustrious career—and admittedly, a bit cantankerous. But he was a brilliant teacher with a rare facility for capturing complex ideas succinctly. Having already covered Stewart Brand’s pace layering and Donella Meadows’ limits to growth, I want to dive into what Ackoff can teach us about today's aviation challenges.

I have never heard a better explanation of a system than the one Ackoff delivered in his famous talks (this one is worth it, just for the opening). His core thesis is timeless: High-performance parts don’t make a high-performance system; high-performing interactions do. As he put it, a system is not the sum of the behavior of its parts, but the product of their interactions. When it comes to the National Airspace System (NAS), or any complex infrastructure, it is vital to remember that distinction.

We should have some sympathy when these complex architectures get modernized. While a legacy component scheduled for replacement can be studied relatively easily in isolation, its web of interactions with other systems is often incredibly hard to discern. For instance, the FAA rolled out a modernized NOTAM (Notice to Air Missions) system recently, but it will take months to completely decommission the legacy infrastructure. Why? Because the old system is deeply intertwined with the daily operations and proprietary software of countless NAS participants.

This brings me to the original comment from my friend Rich that started me down this series of articles on systems thinking. Rich was worried “that the operational risk is inexorably rising but not being revealed until some event occurs that in the previous (fragmented, higher cost, inefficient) NAS would not have been possible”.

Aviation professionals are fond of calling the NAS a System of System (SoS). One useful definition is “A System-of-Systems (SoS) is a special kind of complex system in which new capabilities arise from interacting components that are controlled with varying degrees of independence by multiple owner / operators” (INCOSE). An under-appreciated property of the NAS is its local survivability and resilience. Its built-in redundancies ensure that aircraft keep flying safely even when local nodes or components fail. Herein lies the great modernization quandary: in our necessary search for system-wide efficiency (via initiatives like SMART), we naturally increase data integration and system interdependencies. It is imperative that we ensure the Mission Critical part of the NAS, the one that provides the safety net for air travel, retains its resilience and local survivability.

The pace of change has to match the criticality of the layers, systems have natural limits to growth and feedback loops and, they are more about the richness and reliability of their interactions than merely the efficiency of their components.