The best indicator of the effectiveness of the vulnerability management process is the results from internal vulnerability scans. These scans help identify weaknesses in the system, track the resolution of vulnerabilities over time, and assess how well the organization is addressing security gaps. Regular vulnerability scans provide direct, actionable data to evaluate the success of the vulnerability management program. While third-party audits, budget allocation, and patch testing times are relevant, they do not provide the same continuous and detailed feedback as internal vulnerability scans.