Recently, there has been a surge of interest in adapting object-oriented (OO) concepts, UML, and Unified Process of system development in the Systems Analysis and Design texts. However, there is a question of how to best fit these concepts with the existing coherent discussion of structured approach. This paper addresses some of the intricacies of OO concepts such as complexity of diagrams and models, weak links between phases, and lack of support for designing system components. We would like to recommend that there should be a separate text for the OO methodology and it should not present various OO models according to the phases of the traditional structured approach, rather it should focus on the evolution of the models leading to the design of system components. Furthermore, there should be a standard set of models for the OO methodology as well as a clear definition of steps as an analyst moves from one set of models to the next.