The system analysis and design is all about clearly identifying the functional needs of client and identifying the means to achieve those requirements. However, people cannot reveal all their functional needs at once. The iterative process helps them to identify their needs properly once they see the product. Therefore the spiral model of the system development will be adopted here. It will help ABC company to identify their needs seeing the prototype in various stages of iteration. Spiral Model of System Development is a continuous process of development, which is combination of elements of both design and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up concepts.
Four main stages of Spiral Model of system development are:
1. Determine objective, alternatives and constraints
2. Evaluate alternatives, identify and resolve risks
3. Develop and verify next level
4. Plan for next phase
This model of development combines the features of the prototyping model and the waterfall model. This involves the continuous process of system development. As it combines the prototype and waterfall model most of the activity would be covered. Here the stages of determining actual objectives of system: which is used to know the requirements that might be Business Requirement Specifications (BRS) and System Requirement Specifications (SRS). The requirements are listed taking feedbacks from the executives, sales manager and sales agent of the ABC Company Ltd. Based upon the SRS and BRS the alternatives designs will be proposed. The development team will be in constant touch with the above stakeholders of the ABC Company Ltd.
The second stage will be the evaluation of alternatives, risk analysis, resolving risk and identifying the best alternative. Risks are possible conditions and events that prevent development team from achieving its goals. The primary task for the development team is to enumerate all the possible risks and prioritize them according to importance. The next step is to determine the potential strategies that can help to overcome the risks. Evaluation of these parameters can cause changes at the next steps.
Third stage will be the development of the first prototype. This is the stage where planned product is developed along with further testing. During the first spiral, the overall requirements are not so clear, so-called Proof Of Concept (POC) is created to get the customer‘s feedback. In subsequent spiral, the final product will be developed accordingly.
And the fourth stage is the phase of evaluation of the output of the existing spiral. This phase allows evaluating the output of the online system to date before the project continues to the next spiral.