Which of the following is not included in waterfall model ?

Answer: Risk analysis

Explanation: The traditional waterfall model is a linear, sequential software development process composed of distinct phases. Typical phases include:

• Requirement analysis

• System and detailed design

• Implementation (coding)

• Integration and testing

• Deployment

• Maintenance

Risk analysis is not one of these distinct sequential phases. Instead, risk assessment is typically part of project management activities or is explicitly integrated into iterative models (for example, the Spiral model) that include dedicated risk-management steps.