Check out this Tabletop Exercise article that highlights some of the mechanics involved. Ted Macklin is quoted in the article. He was very involved in the design of our TOPOFF exercise that we did back in 2003, so he has been "around the horn" on the topic of exercises for a long time.
Some people think that having a full scale exercise is best the test of a plan--not in my book. They are very expensive to conduct and sometimes the field players are only "props" for the main action that is happening in Emergency Operations Centers (EOC). If I could only do one type of exercise it would be the tabletop and then for field personnel I'd make sure there were plenty of drills for the technical skills they need.
If I added on more type of exercise it would be a functional one with just EOCs playing and field command staff also participating, but from simulation cells.
