The Slack Principle

Knock-on effects are a feature of complex systems, not a bug to be engineered away. The best decision-makers do not try to prevent second-order effects — they anticipate them, plan for the likely ones, and leave slack in their plan for the ones they could not foresee.

A rigid plan that assumes perfect execution is brittle: any deviation cascades. A plan with buffers built in absorbs the deviation and keeps moving. That slack — extra time, extra budget, extra people — looks like waste to accountants. To anyone who has run a project in the real world, it is the difference between shipping and collapsing.