A project manager entered into a contract with a vendor to build a new system.

According to the PMBOK® Guide 6th Edition, the project manager should provide the failed test results along with the agreed-upon acceptance criteria to support their claim to the vendor. This is because the acceptance criteria are the measurable and verifiable standards that define the quality requirements of the project deliverables. The project manager and the vendor should have agreed on the acceptance criteria before signing the contract. Therefore, providing the failed test results along with the acceptance criteria will show the vendor that they have not met their contractual obligations and that they need to take corrective actions to improve the system quality. References: PMBOK® Guide 6th Edition, page 161, section 5.5.2.1; page 287, section 8.2.2.1; page 375, section 12.1.2.1.