A good analogy is the process an airline pilot goes through before take-off and landing. They go through a �check list� to be sure they are not leaving anything to �chance� or memory. When we consider which is more complicated: the airplane or the human body? But where do we use a checklist? Do we want to go to a hospital where we don�t use a check list to be sure everything we do, those routine things that we know work, aren�t being used.