The article discusses how to design complex software systems using object-oriented analysis and design. It explains the concepts of complexity, the object model, classes and objects, and classification. The researchers outline a method involving notations like class diagrams and process diagrams. They also cover practical aspects like management, staffing, and quality assurance in object-oriented development. The article includes real-world applications such as weather monitoring, inventory tracking, and artificial intelligence cryptanalysis. It concludes with an appendix on object-oriented programming languages.