Q. Explain the software life cycle model that incorporates risk factor.

Ans. The problem with traditional software process models is that they don't deal sufficiently with the uncertainty which is inherent to software projects.

Important software projects failed for the reason that project risks were neglected and nobody was prepared when something unforeseen happened. Barry Boehm acknowledged this and tried to incorporate the project risk factor into a life cycle model. The consequences are the spiral model which was presented in 1986 BOEH86.

Every loop of the spiral from X-axis clockwise through 3600 represents one phase. One stage is split roughly into four sectors of major activities.

• Planning: Determination of alternatives, objectives and constraints
• Risk Analysis: Analyze alternatives as well as attempts to identify and resolve the risks involved
• Development : Product development as well as testing product
• Assessment : Customer evaluation

During the first phase, planning is performed, risks are analyze, prototypes are built, and customers evaluate the prototype. During the second phase, a more refined prototype is built, requirements are documents and validated, and customers are involved in assessing the new prototype. By the time third phase begins, risks are known, and a somewhat more traditional development approach.