The

The "Real" 5-Phases

Software development should not follow the "waterfall" approach as seems to be implied by the previous section of this lecture. What is really needed is interplay between each of the phases. A reinterpretation of the five phases of software development is shown in the graphic below where each phase is connected to every other phase. This approach is sometimes referred to as "spiral" software development.

In addition to having each phase connected to every other phase, Security and Quality Assurance should be connected to every phase as well.

The most important feature of this approach is to notice that the Users (and other stakeholders) are central to the phases and that they need to be involved throughout the entire project.

In addition to not following a linear approach to software development, another modification of the five phases utilizing a component library approach is recommended. In this approach components from the company's software library are used if they exist and if not, then new components are created and utilized. This approach is referred to as "component" software development. The following graphic shows the five phases slightly modified to represent this approach:

While using components in the company library is the approach to take, extra care must be taken not to modify these components and therefore to make them unusable to future as well as previously written programs.

Again you should consider that security and quality assurance are involved throughout this process.

As you progress through these lectures, you should try to develop components that could be used in your future programming. These components could be stored in a dynamic linked library a .dll file like: tools.dll. While the code in this course is in C#, it is possible that some tools developed for this course could be used in C, in C++ or even in Java programs.