A good quality control is the first step to make sure that customer expectations are met.
Quality management is developed in steps:
Quality Planning happens during the Project Planning phase and focuses on how to ensure quality.
Quality Assurance happens during the Project Execution phase and focuses on testing quality.
Quality Control happens during the Project Control & Monitoring phase and focuses on verifying and improving the mechanisms to control quality.
Quality Reviews take place during Planning, quality Tests happen during Executing and Quality Audits happen in all phases to ensure that quality is monitored and under control. The term Audit is sometimes misused when quality Test should be used.