This text takes the approach to SAD developed by the authors in their other texts and adapts it for an object-oriented perspective, faithful to UML and to systems development practices currently in use in many organizations. This text could be used in an introductory SAD class, or a second SAD course where OO approaches are being introduced after structured techniques are taught in the introductory course. It is the first OO SAD book to approach OO from the first chapters and not just an insert of a couple chapters on objects later in the text.