In project management, a business case is a document that justifies the initiation of a project by presenting a current business problem and suggesting ways to solve it through a certain initiative. It evaluates the benefit, cost, and risk of alternative options and provides justification for undertaking a project, program, or portfolio. A business case is developed during the early stages of a project and outlines the why, what, how, and who necessary to decide if it is worthwhile continuing a project. The following are the key elements of a business case:

• Strategic context: The compelling case for change.
• Economic analysis: Return on investment, cost-benefit analysis, and investment appraisal.
• Options appraisal: The options considered, including the do-nothing option.
• Risk assessment: Identification and assessment of risks.
• Investment appraisal: Evidence of how the investment is intended to lead to the realization of the intended benefits.

A business case is a dynamic document that has to be reviewed and updated regularly. A project manager together with a project sponsor is responsible for monitoring its elements to check whether or not the project is still worth the effort. The business case is used as a reference point throughout the whole project lifecycle, providing justification for starting a project, showing the direction of project work, and serving as a record of the recommended option with rationale and evidence to support the decision.