The project manager should treat the client's complaint as a change request and assess the effect on the project's goals. This is because the client's expectation may not have been captured or communicated clearly in the initial debriefing, or the client may have changed their mind after seeing the product. In either case, the project manager should follow the change management process, which involves identifying, documenting, analyzing, approving, and implementing changes that affect the project scope, schedule, cost, quality, or risk.
The project manager should also communicate with the client and the project team about the change request and its impact on the project's goals, such as delivering value, satisfying customer needs, and meeting stakeholder expectations. References: (Professional in Business Analysis Reference Materials source and documents)
* PMBOKGuide, 6th edition, Section 4.6.1, "Perform Integrated Change Control: Inputs"
* PMBOKGuide, 6th edition, Section 4.6.3.1, "Perform Integrated Change Control: Outputs - Change Requests"
* PMBOKGuide, 6th edition, Section 5.6.1, "Validate Scope: Inputs"
* PMBOKGuide, 6th edition, Section 5.6.3.1, "Validate Scope: Outputs - Accepted Deliverables"
* PMI-PBA Guide, 1st edition, Section 6.2.1, "Manage Changes: Inputs"
* PMI-PBA Guide, 1st edition, Section 6.2.2, "Manage Changes: Tools and Techniques"
* PMI-PBA Guide, 1st edition, Section 6.2.3, "Manage Changes: Outputs"