A project manager is assigned to a new project that will use an agile framework. The sponsor requests a cost estimate to build the business case. What should the project manager do?

The project manager should review the completion costs of similar projects because historical data provides a reliable basis for initial cost estimates, especially when little project-specific information is available. This analogous estimating technique is suitable for early project phases like business case development. Ensuring client representative participation in estimation is valuable for detailed planning later, but not the primary action for an initial business case estimate. Including a 20% contingency is a common practice, but it should be based on a preliminary estimate, not the first step itself. Reviewing lessons learned from similar projects is crucial for understanding risks and best practices, but it doesn't directly provide cost figures for the business case; it informs how the estimate might be refined or what risks to consider.