SOFTWARE LIFE CYCLE MODEL(CLASSICAL WATERFALL MODEL) : SOFTWARE LIFE CYCLE MODEL(CLASSICAL WATERFALL MODEL) PRESENTED BY
I MBA INTRODUCTION: : INTRODUCTION: In the 1970’s the first Software Life Cycle Model was developed by Winston Royce, it was called the Waterfall Model .
This was used as the primary life cycle in the industry for over twenty years.
As time progressed increasing demands, budget and time constraints led to the invent of newer life cycles. CLASSICAL WATERFALL MODEL: : CLASSICAL WATERFALL MODEL: Life cycle model is named “classical water fall” because its diagrammatic representation resembles a cascade of waterfalls.
Waterfall model is the most well known software lifecycle development model.
It is very simple to understand and use.
Each next phase in this model must beginning only after the previous phase is over. CLASSICAL WATER FALL MODEL DIAGRAM: : CLASSICAL WATER FALL MODEL DIAGRAM: ITERATIVE WATER FALL MODEL: : ITERATIVE WATER FALL MODEL: In practical software development environment defects introduced in every phase of life cycle.
Errors or defects can be deducted in the same phase as soon as possible.
For example, if a design error is detected during design itself, it can be taken care of much more easily than if identified, say, at the end of the integration and system testing phase. ITERATIVE WATER FALL MODEL DIAGRAM: : ITERATIVE WATER FALL MODEL DIAGRAM: REVIEW PROTOTYPING MODEL: : PROTOTYPING MODEL: Prototyping model suggests that before development of the actual software, a working prototype of the system should be build first.
This is the valuable mechanism for gaining better understanding of the customer’s needs.
Develop prototype is submitted to the customer for his evaluation. Cycle continues until the user approves the prototype. Slide 8: Build prototype Requirement Gathering Quick Design Refine Requirements Customer Evaluation Of the Prototype Design Implement Test Maintain Customer Suggestions Acceptance By Customer PROTOTYPING MODEL DIAGRAM: EVALUTIONARY MODEL: : EVALUTIONARY MODEL: The system is first broken down into several modules or functional units that can be incrementally implemented and delivered.
The evolutionary model facilitates to elicit the exact requirements of the user for incorporating into the fully developed system .
A,B,C are modules of a software product that are incrementally developed and delivered. EVALUTIONARY MODEL DIAGRAM: : A A A B B C EVALUTIONARY MODEL DIAGRAM: SPIRAL MODEL : : SPIRAL MODEL : In the spiral model, software development is carried out in four main phases.
The spiral model enables the developer to understand and react to the risks at each evolutionary level(i.e. Iteration along the spiral).
This model uses prototyping as a risk reduction mechanism and retains the systematic step-wise approach of the waterfall model. SPIRAL MODEL DIAGRAM: : SPIRAL MODEL DIAGRAM: CONCLUSION : CONCLUSION THANK YOU : THANK YOU