The System Level: Overview

At the top of the SNO hierarchy sits the system level, where sustainability is evaluated through three indicators: Resilience, Autonomy, and Harmony. Together, these form RAH: the acronym that captures the essence of what a sustainable system must be.

RAH is derived directly from SiD's sustainability definition. The definition states that a sustainable system "can continue to flourish resiliently, in harmony, without requiring inputs from outside its system boundaries." Each clause maps to one indicator:

• Resiliently maps to Resilience
• In harmony maps to Harmony
• Without requiring inputs from outside maps to Autonomy

If a system scores well on all three, it is sustainable. If any of the three is critically weak, the system will eventually fail, regardless of how strong the other two are.

How RAH Indicators Work

The RAH indicators are broad by design. There is no uniform formula that works for every system. They require assessment on a case-by-case basis, informed by the network parameters and object-level data below them. System indicators tell us about the performance of the system as a whole, and they are the highest order of evaluation you can perform.

The three indicators respond to each other, but not linearly:

• Increased Harmony usually supports higher Resilience (a just system faces less internal strife)
• Very low Autonomy hurts Resilience (dependency makes you vulnerable)
• Very high Autonomy can also reduce Resilience (isolation cuts you off from support networks)
• A system can be Resilient and Autonomous but without Harmony it becomes something nobody wants: a hardy empire impossible to overthrow

This last point is critical. RAH is not a checklist where more is always better. It is a balance. The interplay between the three determines the character of the system's sustainability.

The next three units explore each indicator in depth.