If you’ve been charged with developing the case for a new project at your company, imagine you’re telling a story. The narrative starts, as all good ones do, with a problem. This is the business need you’re trying to solve. Then, identify the characters: the stakeholders who have the authority to approve or reject your business case; the beneficiaries who stand to gain from your proposal; and the subject-matter experts who will clarify how to solve the problem. Next you’ll consider alternatives for meeting the business need—different ways your story might play out. After making the best choice, you’ll create a very high-level project plan. This is the plot. Then estimate the costs and benefits to determine the return on investment (ROI), which is the satisfying end. Remember this isn’t a mystery novel—your story needs to be clear and easy to understand.
Adapted from the HBR Guide to Building Your Business Case.