What is QA? What is QC? Similarities and differences between them? The article below explains Quality Assurance (QA) and Quality Control (QC) and clarifies how they relate and differ in project management.

1. Quality Assurance

Quality Assurance (QA): It is part of the executing process group and a process-based approach to ensure that the processes and methods related to producing final products/deliverables are free of defects, enabling them to meet quality objectives (as described in the Manage Quality process).

- In simple terms: QA focuses on processes. Its primary purpose is to prevent defects in products/deliverables by evaluating the effectiveness of current Quality Control processes and implementing necessary changes to correct any process-related deficiencies.

- Quality Assurance is a proactive process involving understanding the requirements and establishing controls and activities (such as quality audits, training, etc.) to achieve the intended quality objectives.

- QA is used to manage the quality of processes.

2. Quality Control

Quality Control (QC): It belongs to the monitoring and controlling process group and covers the activities and measures performed to meet the product or deliverable quality requirements (as described in the Control Quality process).

- In simple terms: QC focuses on the quality of products/deliverables. Its main purpose is to ensure accuracy and to detect defects in deliverables.

- Quality Control is a reactive process that inspects products/deliverables to identify any non-conformance.

- QC is used to verify product quality.

As noted above, QA and QC processes are closely related and interact with each other. QA defines the processes for implementing QC, while feedback from QC influences QA. If defects are found through Quality Control, this information is used by Quality Assurance to determine any corrective or preventive actions needed. That is why “Quality Control Measurements” serve as an input to the Manage Quality process within the quality management process group.

Example illustrating the differences between QA and QC in a project:

• Quality Control will inspect the final product based on quality requirements stated in the Quality Management Plan and report results as Quality Control Measurements.
• Quality Assurance will use these Quality Control Measurements and other information to reassess whether the methods and processes used in the project are appropriate, and whether QC is evaluating the most accurate and effective metrics, etc.

3. Comparison between Manage Quality and Control Quality

Manage Quality is sometimes called Quality Assurance, although Manage Quality has a broader definition than quality assurance, as it is used in non-project work. In project management, the focus of quality assurance is on the processes used in the project. Quality assurance is about using project processes effectively. It involves following and meeting standards to assure stakeholders that the final deliverable will meet their needs, expectations, and requirements. Manage Quality includes all the quality assurance activities, and is also concerned with the product design aspects and process improvements. Manage Quality work will fall under the conformance work category in the cost of quality framework.

Control Quality is performed to measure the completeness, compliance, and suitability of the product or service before user acceptance and final delivery. This is done by measuring all steps, attributes, and variables used to verify conformity or compliance with specifications defined during planning.