System Analysis and Design
Overview
In the System Analysis and Design phase, the software development process, the software’s overall structure, and its nuances are defined. In terms of the client/server technology, the number of tiers needed for the package architecture, the database design, the data structure design, etc, are all defined in this phase. A software development model is created. Analysis and design are crucial in the whole development cycle. Any glitch in the design phase could be very expensive to solve later in the software development. Much care is taken during this phase. The logical system of the product is developed in this phase.
The exceptional or foolish programmer might begin coding without a good design.
Programmers who do so may find themselves going back to modify pieces of code they’ve already written as they move through the project. With a good design, the likelihood of this happening will be reduced dramatically. The end result is a program that will behave in the way it was intended and will generally have a shorter overall program development time.
Design in the SDLC encompasses many different elements. Here is a list of the different
components that are ‘designed’ in this phase:
- Input
- Output
- Processing
- Files
By the end of the design phase, we hope to have a formal Requirements Statement for the program and a rough sketch of the user interface.
Most programs are designed by first determining the output of the program. If you know the program’s output, you can determine the input needed to produce that output more easily. Once you know both the output from and the input to the program, you can determine what processing needs to be performed to convert the input to output. You will also be able to consider what information needs to be saved and what sort of file.
While doing the Output and Input designs, more information will be available to add to
the Requirements Statement. It is also possible that a first screen design will take shape, and at the end of these designs, a sketch will be made of what the screen will look like.