For those of us who have slogged through ISD projects using the ADDIE model and found ourselves behind schedule or over budget, here is another methodology. SAM or the Successive Approximation Model can be an antidote to the analysis paralysis which sometimes befalls strict constructionists who utilize the ADDIE methodology. I am neither a defender nor detractor of ADDIE which I have used quite effectively on many occasions to guide me through complex projects. SAM looks very promising and in my view is more akin to the rapid prototyping school of thought. Here is a brief look at SAM from Allen Interactions.
With the use of any of these models it is not the arrow, but rather the archer who ultimately decides the success or failure of any project. The model is but a tool to aid the designer along the way.