Some are quite poor. If your only tool is a hammer, then all problems are nails. Yes, Evaluate Cost means for each alternative. There are some more things to do there I incorporated in to the revised graphic. Yes, Choose means pick an alternative or a combination of them or iterate again.
Assumptions have to be worked in throughout.
That process is iterative. I added some arrows to indicate iteration with nearby blocks. I really try to keep an open mind and evaluate things rationally the way the model suggests. Not that easy though. Ray A RiskAnal colleague on smoking.