GLOSSARY

Quality Assurance and Quality Control (QA/QC)

Last updated October 27, 2026

What does QA/QC mean?

QA/QC stands for quality assurance and quality control. The two terms are often written together because most quality programs run both, but they describe different work.

Quality assurance is the set of planned activities that build quality into a process so that defects do not occur. Quality control is the set of operational checks that catch defects in a finished product before it reaches a customer. QA acts on the process. QC acts on the product.

A quality management system is where both are documented, connected, and made auditable.

Quality Assurance (QA) is a proactive process aimed at preventing defects by refining manufacturing procedures, while Quality Control (QC) is a reactive measure that identifies defects in finished products, ensuring they meet requirements before reaching customers. Medical device engineers sometimes use the terms interchangeably, but a clear understanding of the difference between the two brings clarity to the structure of the whole quality process. For a deeper look at how the two functions divide in practice, see QA and QC in the medical device industry.

FREE DOWNLOAD: Click here to download Checklist to Evaluate Your Quality Control Process.

Quality Control vs. Quality Assurance

QA and QC answer two different questions. QA asks whether the process is capable of producing a conforming product. QC asks whether this particular product conforms.

Attribute	Quality Assurance (QA)	Quality Control (QC)
Goal	Prevent defects before they happen	Find defects before the product ships
Focus	The process that makes the product	The product the process makes
Approach	Proactive	Reactive
Timing	Across the full product lifecycle, from design through production	At defined checkpoints, usually at or near the end of production
Who owns it	Quality leadership, plus every function that touches the process	A designated inspector, technician, or test lab
Typical activities	Writing and approving procedures, design controls, supplier qualification, training, internal audits	Incoming inspection, in-process testing, final release testing, sampling against acceptance criteria
Output	Repeatable, documented processes and audit-ready records	Pass or fail results against predetermined acceptance criteria
Where it lives in a QMS	Design controls, purchasing controls, production and process controls, training records	Inspection and test records, nonconformance records, acceptance activities

Comparison of quality assurance and quality control activities in a medical device quality system

Quality Assurance: It's All About The Process

Quality assurance can be defined as the activities for ensuring quality in the processes by which products are developed. This proactive process includes many methods, all with the purpose of preventing defects in the final product. Effective quality managers engage in quality assurance by improving product development and testing processes so that defects do not arise when the product is being developed.

The quality management system itself is a quality assurance tool. It holds the quality policies, procedures, and quality standards that govern how a product gets made, and it is what an auditor reads to judge whether those standards are actually being followed rather than merely written down. Purchasing controls ensure that the raw materials used to manufacture a product consistently meet acceptable standards. Production and process controls are designed to create uniformity and consistency in the manufacturing process, helping to ensure the consistent production of quality goods.

Quality Control: It's All About The Product

While much of your QMS will be focused on assuring the quality of processes, quality control represents a set of activities that focuses on identifying defects in the products that you create. Quality control is typically the last controlled process that a product will go through before it is shipped. As such, an effective quality control process acts as a buffer between defective products and the customer. A perfect QC process would ensure that defective products are always identified and never make it to a store shelf or into the hands of a customer.

Quality control is typically handled by a specific person or team that tests finished products against predetermined acceptance criteria. Those criteria come out of quality assurance work: they are set during design and documented in the quality management system, which is why a QC result is only as meaningful as the standard it is measured against.

Integrating Quality Assurance & Quality Control in a Quality System

Greenlight Guru QMS offers the ideal support system for both quality assurance and quality control procedures at your medical device company. Product specifications are created in the product development stage of your medical device and documented in your QMS under the Design Controls section. These specifications set the expectations for how your product can be effectively manufactured.

Purchasing controls, production and process controls, and training guidelines for staff all live in your QMS and will need to be continuously updated in response to any defects you discover. Internal audits are also an important aspect of quality assurance, and any FDA audit will require that you present the findings of any internal audits you have conducted.

Quality control feeds back into quality assurance through the CAPA process, whose documents are all stored in your QMS. A non-conforming product creates a need for corrective and preventive actions, leading to a root cause analysis and a refinement of your procedures to help reduce incidences of non-conforming products in your inventory. Run well, quality assurance and quality control stop being two separate reporting lines and start being one quality management loop: QC findings change procedures, revised procedures change what QC finds next, and the quality standards a company holds itself to move with them. Greenlight Guru QMS keeps both halves in one system of record, so the connection between a nonconformance and the procedure it should change is traceable rather than reconstructed.

How QA and QC map to medical device regulations

Medical device regulations do not use "quality assurance" and "quality control" as their organizing structure, which is part of why the terms get blurred in practice. What regulators ask for is a quality management system in which both kinds of activity are defined, performed, and recorded. For medical device manufacturers, the two frameworks that set those expectations are ISO 13485 and the FDA Quality Management System Regulation (QMSR).

In that framing, most of what a team calls QA shows up as system-level requirements: management responsibility, document and record control, design controls, purchasing controls, training, and internal auditing. Most of what a team calls QC shows up as acceptance activities: inspection and test, the records proving each was performed, and the handling of product that fails.

FREE DOWNLOAD: Click here to download Checklist to Evaluate Your Quality Control Process.

QA and QC: common questions

Is quality assurance proactive or reactive?

Quality assurance is proactive. It is designed to prevent defects by shaping the process before and during production. Quality control is the reactive half of the pair: it inspects and tests output after the work is done. A quality program needs both, because prevention is never perfect and detection alone never improves the process.

Which comes first, QA or QC?

QA comes first. The procedures, design controls, and acceptance criteria that QA establishes are what QC later inspects against. QC results then feed back into QA through nonconformance and CAPA records, so the two run as a loop rather than a sequence.

Can QA and QC be the same person?

At a small company they often are, and that is workable as long as the QC decision stays independent of the pressure to ship. Once volume grows, most teams separate them so that the person judging whether a product passes is not the same person accountable for the schedule it passes on.

What is the difference between QA and a QMS?

QA is a function. A quality management system is the system of record that holds it. The QMS stores the procedures, training records, design controls, and audit findings that QA produces, alongside the inspection and test records that QC produces.

What is the difference between quality assurance and quality compliance?

Quality assurance is about whether the process reliably produces a good product. Quality compliance is about whether the process and its records satisfy an external standard or regulation. The two overlap heavily, but a process can be compliant on paper and still produce defects, which is why assurance work does not stop at the audit.