1.3.5 Principe 6 : Maintenir un mélange équilibré de résilience et d'efficacité.

Ulanowicz et al. also establish the balance of resilience and efficiency required for systemic health using the balance of sizes. Ulanowicz found that healthy ecosystems maintain a balance of both efficiency and resilience, noting that the factors that lead to efficiency (big size, high capacity, streamlining) are opposed to those that lead to resilience (small size, variety, dense connectedness). In order to determine the “Window of Vitality,” or the range of equilibrium within which healthy systems fell, he used data from natural ecosystem. He theorized that extremes are not noticed because too much efficiency leads to brittleness, while too little small-scale diversity leads to low-energy stagnation.

This study explains why placing too much focus on efficiency and “economies of scale” can be detrimental to an organization’s overall health. This finding was utilized by Lietaer et al. to demonstrate how today’s overemphasis on effectiveness and size in business and banking, respectively, led to economic and banking crises. Ulanowicz’s Window of Vitality statistic can be used to identify a resilient and effective equilibrium.