This is the highest level in the information system. It is used to organize performance data into a relational database in an effort to evaluate alternative business decisions.
The database could be used to decide if strategic alliances are profitable or if manufacturing capacity should be increased.
The difference between decision analysis and strategic is that decision analysis can be things you look at on a regular basis or have less impact on the company, while stratgic planning have a greater company impact. The concept is similar.