You are completing enterprise analysis.

A business case is a document that provides the rationale and justification for initiating a project or an investment. It describes the business problem or opportunity, the proposed solution, the expected benefits, costs, risks, and assumptions. A business case also includes an analysis of the alternatives and a recommendation for the best option. A business case helps management to make a go/no go decision based on the value proposition and the return on investment of the project. A business case is one of the key outputs of the enterprise analysis process, which involves defining the business need, assessing the capability gaps, determining the solution approach, defining the solution scope, and defining the business case1234. References: 1: BABOK Guide v3, section 3.4, pages 68-77 2: CBAP / CCBA Certified Business Analysis Study Guide, chapter 4, pages 107-108 3: Business Analysis Techniques: Developing the Business Case, pages 25-26 4: How to Write a Business Case: 4 Steps to a Perfect Business Case Template