"Every increase in efficiency increases vulnerability.
Efficiency is seductive because it looks like professionalism. The system feels tighter, faster, and easier to explain. Cutting slack can feel like removing failure, when it is often removing your options.
Dörner’s point is that efficiency consumes slack. Slack is what absorbs surprises: extra capacity, redundancy, time to think, and room to contain failure. Remove it, and the same system becomes more brittle under the same load. The first break is rarely where you cut; it is where the system was already thin.
Choose vulnerability deliberately. Name what you gain, name what you lose, and keep one backstop that makes the loss survivable. If you cannot name the backstop, you are not buying efficiency; you are buying fragility. Slack is what lets you recover without heroics.