A quality assurance process should include:

Trend analysis can be a tool used within quality control or quality assurance to monitor performance, but it is not the overall scope or a mandatory inclusion of the quality assurance process itself.

Human resource management is a separate knowledge area focused on managing project personnel, distinct from the technical focus of quality assurance on processes and deliverables' quality.

Quality assurance is an ongoing process that aims to ensure that the project's processes and deliverables meet the defined quality standards. This inherently includes continuous service improvements, as QA activities often identify opportunities to enhance processes, reduce defects, and increase efficiency over time, driving better quality outcomes and ensuring the project continues to meet evolving quality needs.

Cost estimation is part of project cost management and occurs primarily during planning, not as a direct component or ongoing activity of the quality assurance process, which focuses on adherence to quality standards.