When you know that an undesirable situation is going to happen, you may be able to do something ahead of when it would occur, either to prevent it from happening or to reduce the impact that might be felt when it does happen. Methods to do this includes reinforcing and setting up counterweights so the problem is managed at all times.
A. If it will be necessary to do an action with both harmful and useful effects, this action should be replaced with anti-actions to control harmful effects.
Buffer a solution to prevent harm from extremes of pH.
B. Create beforehand stresses in an object that will oppose known undesirable working stresses later on.
· Pre-stress rebar before pouring concrete.
- Masking anything before harmful exposure: Use a lead apron on parts of the body not being exposed to X-rays. Use masking tape to protect the part of an object not being painted