Spiral Approach

Managing IT Projects

Build & Test - Spiral Model

The spiral method is similar to the prototyping approach to systems development. However, the Spiral method adds an assessment of the risks inherent in the construction. At each iteration, the development team, in conjunction with the end-user, looks at the risks, costs and alternatives open to the user. In each iteration, the user requirements are refined and a more complex prototype is produced either by building on the existing version or by creating a new one.

There are four stages in the Spiral method:

Planning -	where the objectives and constraints of the application are identified and alternatives defined

*Risk Analysis -*	where alternatives are considered, risks are identified and resolved (where possible). Risk analysis also results in a GO/NO GO decision having to be made in which the project may be abandoned if the risks are considered too great.

*Engineering -*	where the next version of the application is developed. The development process could use Life Cycle, Prototyping or any other method depending on the certainty of the specifications

*Customer Evaluation -*	where the end user examines and tests each evolution of the application, clarifies the requirements, extends the functionality and reports on faults testing.