Same reason you might write out other specifications or maybe make a flow diagram of states something might go through in your application. Certainly, with com

Same reason you might write out other specifications or maybe make a flow diagram of states something might go through in your application. Certainly, with complex relations between various tables, having a design tool like this can help you visualize what you are doing. This in turn can help you in spotting things you might otherwise overlook. Some of it depends on the sort of database work you do and how complex your database will be. If you only have a few simple tables with virtually no relations between them, this might indeed be overkill for you.