A business case is a structured proposal that justifies the future implementation of a project or solution. It identifies use cases, quantifies expected outcomes, confirms project affordability and practicality, and explores potential risks and blockers.

The HMT Green Book model and the 'desirability, feasibility, viability' approach are recommended for building a business case for a digital twin project . It involves examining costs and benefits, consolidating them into a coherent plan, and ensuring alignment with the organization's goals and strategies. The business case outlines the purpose, opportunities, problems to be solved, and the benefits of implementing a digital twin.