A supplier was appointed to deliver software and an internal project manager was assigned. The supplier claims no technical development or testing is required from the customer. The project manager wants to confirm this with stakeholders. What should the internal project manager do first?

The project manager's priority is to ensure a shared understanding of project requirements and deliverables, especially when a supplier makes a significant claim about customer involvement. Hosting an alignment session with stakeholders is the best first step because it allows for direct discussion, clarification, and formalization of expectations regarding customer responsibilities, including testing. This proactive approach prevents misunderstandings and potential scope creep or gaps later. Developing a user acceptance testing plan is premature without confirming the need for customer testing. Telling the supplier that customer testing is required without stakeholder input is an assumption. Distributing the project plan is important but doesn't address the immediate need to confirm stakeholder expectations regarding the supplier's claim.