This white paper outlines the process of constructing a Business Case for investing in Project Portfolio Management (PPM) tools. It begins by identifying the reasons organizations implement PPM solutions, primarily to enhance decision-making regarding project selection, resource allocation, and benefit realization. The document details the components of a compelling Business Case, including the benefits, costs, and expected Return on Investment (ROI). It categorizes benefits into direct cost savings, tangible benefits, and intangible benefits, emphasizing the importance of measurable outcomes. The paper also discusses the costs associated with implementing PPM tools, covering software licenses, training, and process updates. Additionally, it presents independent research findings that illustrate the financial advantages of PPM tools, including reduced project budget overruns and improved staff productivity. The conclusion reiterates the necessity of a well-supported Business Case to justify the investment in PPM tools, ensuring alignment with organizational goals.