Which of the following activities is part of the Plan phase in ISO 9001?

The activity that is part of the Plan phase in ISO 9001 is understanding the organization's context. This phase involves identifying and analyzing both internal and external issues that could impact the quality management system (QMS) and its ability to achieve its intended outcomes. By understanding the organization's context, a company can align its quality objectives with its strategic direction and enhance its ability to satisfy customer requirements and other relevant stakeholders.

In this phase, it's crucial to consider factors such as the marketplace, regulatory framework, and potential risks and opportunities. This foundational understanding helps in setting measurable quality objectives and defining the processes necessary to achieve them.

Establishing customer requirements, while important, is more closely related to determining customer needs and expectations rather than directly assessing the organizational context. Performing quality audits and implementing corrective actions are activities that typically belong to the Act phase and Check phase, respectively, rather than the planning phase.