Programming Visual Basic .NET, Second Edition

Object-Oriented Analysis and Design

The steps to take before programming anything are analysis and design. Analysis is the process of understanding and detailing the problem you are trying to solve. Design is the actual planning of your solution.

With trivial problems (e.g., computing the Fibonacci series^[6]), you may not need an extensive analysis period, but with complex business problems, the analysis process can take weeks or even months. One powerful analysis technique is to create what are called use-case scenarios, in which you describe in some detail how the system will be used. Among the other considerations in the analysis period are determining your success factors (how do you know if your program works) and writing a specification of your program’s requirements.

Once you’ve analyzed the problem, you design the solution. Key to the design process is imagining the classes you will use and their inter-relationships. You might design a simple program on the fly, without this careful planning; but in any serious business application, you will want to take some time to think through the issues.

There are many powerful design techniques you might use, most of which are beyond the scope of this book. One interesting controversy that has arisen recently is between traditional object-oriented design on the one hand^[7] and eXtreme programming on the other.^[8]

There are other competing approaches as well. How much time you put into these topics will depend, in large measure, on ...