Waterfall Model
Waterfall approach was first SDLC Model to be used widely in Software Engineering to ensure the project success. In The Waterfall approach the whole software development and divided into separate phases. In Waterfall typically, model, the outcome of one phase acts as the input for the next phase sequentially.
Following is a diagram representation of different phases of waterfall model.
Waterfall Model Application
Every software developed is different suitable of SDLC approach to be followed based on the internal and external factors.
• Technology is understood and is not dynamic
• Requirements are very well documented for clearing and fixing propose.
• Ample resources …show more content…
• Not a good model for object-oriented projects.
• Poor model ongoing projects.
Iterative Model design
Iterative model process starts with a simple implementation of the software requirements and iteratively enhances the evolving versions until the full system is implemented. At each iterative design modifily and new functional capabilities are added. The basic behind this method is to develop a system through cycles (iterative) and in smaller portions at a time (incremental).
Following is the pictorial representation of Iterative and Incremental model
Iterative Model Application
Like other SDLC models, Iterative and incremental development has some specific applications in the software industry. This model is mostly used in the following ;
• Requirements of the complete system are clearly defined and understood.
• Major requirements must be defined
• There is a time to the market constraint.
• High risk features and goals which may change in the future.
Iterative Model …show more content…
A software project repeates the passes through these phases is called Spirals.
• Identification
• Design
• Construct or Build
• Evaluation and Risk Analysis
Following is a diagrammatic representation of spiral model listing the activities in each phase:
Spiral Model Application
Spiral Model is used in the software industry as it is in the natural development process of any product learning with also involves minimum risk for the customer as well as the development firm. Following are the uses for Spiral model:
• When there is a budget constraint and evaluation is important.
• For medium projects.
• Long-term project commitment because of potential changes to economic priorities as the requirements change with time.
Advantages
• A highly custom product can be develop used
• It is suitable for high projects where business needs maybe unstable.
• Changes can be introduced later in the life cycle as well. And coping with these changes isn’t a very big headache for the project manager.
Disadvantages
• Skills required, to evaluate and review project from time to time, need expertise.
• Cost involved in this model is usually high.
• Amount of documentation required in intermediate stages makes management of project very complex