To investigate the potential improper activity indicated by the buyer being listed as the requisitioner on many purchase orders, the procurement standard operating procedures (SOPs) will be most useful. The SOPs will provide detailed guidelines on the procurement process, including roles and responsibilities, which can help identify if any rules or protocols have been violated. Leadership and transformation management documents stress the importance of adhering to SOPs to ensure compliance and transparency in procurement activities. By reviewing the SOPs, the supply manager can compare the buyer's actions against established procedures to determine if there has been any improper conduct. Reference highlight the role of SOPs in maintaining accountability and integrity within supply management operations.