Comprehensive and Detailed 150–300 words Explanation (paraphrased from AgilePM/DSDM guidance):

In AgilePM, the Business Sponsor is the project’s ultimate decision-maker and the role accountable for ensuring continued business justification. This includes owning the investment decision, securing and sustaining funding, and maintaining senior-level commitment to the business opportunity. A lack of commitment represents a threat to the viability of the Business Case; managing and mitigating that risk sits squarely with the Sponsor. The Sponsor establishes clear objectives, champions the initiative across the organization, removes high-level impediments, and ensures that governance supports timely decisions. While the Business Visionary articulates and safeguards the solution vision and value outcomes, that role does not control organizational commitment or funding at the enterprise level. Similarly, Business Advisors provide specialist input but do not own commitment or investment risk. Therefore, where commitment to the business opportunity is wavering or unclear, the Business Sponsor is responsible for intervening—reconfirming the Business Case, rallying stakeholder support, and aligning investment, scope and timescales—so the project remains justified and deliverable.