Most people allow similar use of the two words Quality Management and Quality Assurance to refer to the same definition. Both words, however, are distinct in both sense and intent. Here is the original source.
The description and clarification of both words is obviously quite clear.
Let us begin by reviewing the concepts of quality assurance and quality management as per various standard bodies.
As per the American Performance Council, ASQ
QA is described as “The organized and structured activities carried out in a production system to fulfill the quality specifications for a product or service.”
QC is described as “The observation techniques and activities that are used to meet quality requirements.”
By ISO 9000
QC is described as “A part of quality control that is geared towards meeting quality requirements”
QA is described as “a part of quality management that is based on ensuring that quality specifications are met”
There are obviously noticeable variations between Quality Assurance and Quality Control.
The most noticeable distinction between quality assurance and quality control is that QC is method focused when QC is commodity driven.
Quality assurance is focused primarily towards preventing defects. This requires specific processes, procedures , and techniques for determining those fields that are beyond the company’s requirements and quality for its goods and services.
At the other side, quality control refers to procedures and guidelines aimed at anticipating any possible mistake that might arise to discourage that from happening just before it happens.
The distinction in QA and QC is that while quality assurance guarantees that what you’re doing is the correct stuff in the best manner, while QC guarantees that what you’ve achieved outcomes are as planned.
QA is a positive feature and a quality control system thus provides a greater level of work.
QC is concerned with ensuring that the job is performed adequately, so that it is legal. Once the research has been completed it works on fixing anomalies. Or we may claim, the operations of quality assurance function as corrective steps.
The disparity between QA and QC is a power and control discrepancy too. QC is under production supervision while QA is controlling progress.
This is also observed that although certain companies rely mostly on QC, some concentrate primarily on quality control. All such systems must be subject to careful assessment and supervision to maintain effective operation and reliable goods.