Post root cause analysis (RCA) impact assessment, corrective and preventive actions (CAPA) development, and effectiveness checks are critical components of an investigation to ensure compliance with regulatory standards. This chapter examines the integrated approach to managing investigations, emphasizing the alignment of RCA with CAPA development and the implementation of effectiveness checks. CAPA strategies are systematically designed to address root causes, leveraging cross-functional expertise and evidence-based methodologies. Robust effectiveness checks verify the sustainability of CAPA outcomes through predefined metrics, process monitoring, and periodic reviews, ensuring that systemic vulnerabilities are mitigated.