Software Project ManagementWaterfall model By : Mohammad umair khan
The waterfall model is a model which was developed for software development; that is to create software. It is called as such because the model develops systematically from one phase to other in a downward fashion, like a waterfall.
The history of the Waterfall model is somewhat disrupted. Itis often said or believed that the model was first put forth byWinston Royce in 1970 in one of his articles; whereas he didnot even used the word “waterfall.” In fact Royce laterpresented this model to depict a failure or a flaw in a non-working model. So later on, this term was mostly used inwriting about something that is often wrongly done in theprocess of software development – like a commonmalpractice.
Phases of waterfall• Definition Study / Analysis:During this phase research is being conducted which includesbrainstorming about the software, what it is going to be andwhat purpose is it going to fulfill.• Basic Design:If the first phase gets successfully completed and a wellthought out plan for the software development has been laidthen the next step involves formulating the basic design of thesoftware on paper.• Technical Design / Detail Design:After the basic design gets approved, then a more elaboratedtechnical design can be planned. Here the functions of each ofthe part are decided and the engineering units are placed forexample modules, programs etc.
• Construction / Implementation: In this phase the source code of the programs is written.• Testing:At this phase, the whole design and its construction is putunder a test to check its functionality. If there are any errorsthen they will surface at this point of the process.• Integration:in the phase of Integration, the company puts it in use after the system has been successfully tested.• Management and Maintenance:Maintenance and management is needed to ensure that thesystem will continue to perform as desired.
Requirements will be set and these wouldnt be changed. As everything is documented a new team member can easily understand whats to be done. Implementers have to follow the design accurately. A waterfall model helps find problems earlier on which can cost a business less than if it was found later on. reduces the risk of schedule slippage, or of customer expectations not being met.
If requirements may change the Waterfall model may not work. Many believe it is impossible to make one stage of the projects life cycle perfect. Difficult to estimate time and cost for each stage of the development process. Constant testing of the design is needed. It does not allow for much reflection or revision. Designs that look feasible on paper turn out to be expensive or difficult in practice.
Whether you should use it or not depends largely on how well you believe you understand your customers needs The model is recommended for use only in projects which are relatively stable and where customer needs can be clearly identified at an early stage.
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