The Spiral Model

11 Mar

Modern day Information systems used by businesses follow models of development I would like to examine one such model in detail. This is a commonly used model called the Spiral Model.

The spiral model, also known as the spiral lifecycle model, is a systems development lifecycle (SDLC) model used in information technology (IT). This model of development combines the features of the prototyping model and the Waterfall Model. The spiral model is favored for large, expensive, and complicated projects. This model is often used by large multinational companies and is very expensive to implement firms such as KPMG have utilized this model to great effect.

The steps in the spiral model can be generalized as follows:

  • The new system requirements are defined in as much detail as possible. This usually involves interviewing a number of users representing all the external or internal users and other aspects of the existing system.
  • A preliminary design is created for the new system. Based on the requirements of the company.
  • A first prototype of the new system is constructed from the preliminary design. This is usually a scaled-down system, and represents an approximation of the characteristics of the final product. It will take time for all the minor details of the information system to be ironed out, this will be achieved through discussions and company meetings to decide the best design to go with.
  • A second prototype is evolved by a fourfold procedure: (1) evaluating the first prototype in terms of its strengths, weaknesses, and risks; (2) defining the requirements of the second prototype; (3) planning and designing the second prototype; (4) constructing and testing the second prototype. This prototype should be close to the final information system.
  • At the customer’s option, the entire project can be aborted if the risk is deemed too great. Risk factors might involve development cost overruns, operating-cost miscalculation, or any other factor that could, in the customer’s judgment, result in a less-than-satisfactory final product. This is a critical step as if the company goes ahead with the project and it fails it can lead to the firm loosing a large amount of revenue.
  • The existing prototype is evaluated in the same manner as was the previous prototype, and, if necessary, another prototype is developed from it according to the fourfold procedure outlined above.
  • The preceding steps are iterated until the customer is satisfied that the refined prototype represents the final product desired.

The final system is constructed, based on the refined prototype. The Spiral Model is a well regarded method that is used worldwide and has proven to be effective.





2 Responses to “The Spiral Model”

  1. sad111708665 March 11, 2013 at 2:57 pm #

    This is an excellent blog! Well done 😄😄😄

  2. sad112540853 March 13, 2013 at 7:58 pm #

    Great blog, it was really interesting and it had a lot of detail 😀

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