Systems need to be managed not only for productivity or stability, they also need to be managed for resilience—the ability to recover from perturbation, the ability to restore or repair themselves.

But you can’t optimize systems in a context that’s changing, especially if it’s changing in unpredictable ways. Removing inefficiencies when circumstances are as anticipated means that there isn’t much slack in the system to respond when the unanticipated happens. Optimization is intrinsically brittle , because it’s about closely matching the outpu