Schwartz identifies eight steps in the process. Inc. But narrowing the original decision question gives you much sharper insights. Some driving forces effect everyone the same. Everyone, for instance, is driven by the need to cut costs, and the need to incorporate new technologies. But unless one of your potential partners is markedly better or worse than other people at doing these things, they are not differences that make a difference.
Some forces are more important than others.
Whether the market will grow may not be as important as whether new players enter the market. And some forces are far more certain than others. Local housing and population patterns usually change fairly slowly. On the other hand, other questions are highly uncertain. The most critical driving forces will be those that are both very important and highly uncertain.