Introduction 

• The Skills of object-oriented analysis and design (OOA/D) are essential for the creation of well-designed, robust, and maintainable software using object technologies and languages such as Java, C++, Smalltalk, and C#.
• Knowing an object-oriented language (such as Java) is a necessary but insufficient first step to create object systems. Knowing how to "think in objects" is also critical.

What Is Analysis and Design? 

Analysis emphasizes an investigation of the problem and requirements, rather than a solution. For example, if a new computerized library information system is desired, how will it be used? "Analysis" is a broad term, best qualified, as in requirements analysis (an investigation of the requirements) or object analysis (an investigation of the domain objects). 

Design emphasizes a conceptual solution that fulfills the requirements, rather than its implementation. For example, a description of a database schema and software objects. Ultimately, designs can be implemented.

Analysis and design have been summarized in the phase: do the right thing (analysis), and do the thing right (design).