Part 1: Comparison of two Interaction Design Models. I have elected to compare the Waterfall model and Spiral Model. The Waterfall model is credited to Winston W. Royce in an article he published in 1970, although he did not refer to it as "Waterfall" in the commentary (Royce 1970). The Waterfall model is comprised of series of steps which include: gathering requirements; analysis; design; coding; testing and debugging; and acceptance. It is designed to be a simple one way process where one step must be completed and fully reviewed before the next can be undertaken. In this model the phases do not overlap and movement is from one phase to the following, with no opportunity to reverse the movement back to the previous stage. Advantages:
• It is the easiest to implement since it is linear in nature. • Each phase is completed at a time and reviewed. • There is clear compartmentalization of work and control in the model. Due to the compartmentalization, it is easier to set schedules and track implementation. • This model is the easiest to implement in the eyes of most of the mangers, due to its linear model. • Programmers are users.
• The documentation and testing happens at the end of each phase, which helps in maintaining the quality of the project.
• It is document Centric which can make it difficult for the customer to understand. • It is not user centered.
• The project is not partitioned in phases in a flexible way. • Requirements that is inflexible.
As the name suggests the spiral model is a design which provides flexibility to the model design and implementation. As the shape implies there is always a way to go back. While most of the documentation and fundaments are derived from the waterfall model, the major distinguishing feature of the...