Thinking QA, QC and testing mean the same thing is a common misconception. While they may be closely related, they do refer to very specific and separate activities and should therefore be differentiated.
According to ISO 9000 Definitions Quality Control is “The operational techniques and activities that are used to fulfill requirements for quality” and Quality Assurance are “All those planned and systematic activities implemented to provide adequate confidence that an entity will fulfill requirements for quality”.
Quality Assurance includes the Quality Control processes, Product 
Quality and other Quality Management business systems. It means Quality Control is a part of Quality Assurance.
In simple words when we compare quality assurance with quality control; the quality will be the defects prevention and the goal will be the zero defects for Quality Assurance whereas quality will be defect identification and goal will be the process of control to reduce the defects for Quality Control.
Typical Steps for:
 |
The main outcome of the Problem Identification stage is to set the overall purpose and objectives of the risk assessment and to determine the likely data requirements. | It is a frequent part of solving problems and satisfying curiosity. |
 |
To gather information that helps you determine the nature of a problem encountered on your system. | Based on number of problems occurring in the area under study. |
 |
To correct the problem identified in QC process. | Each process is identified with a unique name/number. |
 |
Process of control to reduce the defects for Quality Control. | A process can be defined as “a logical series of related transactions that converts input to results or output” (Andersen 1999). |
 |
It is a series of actions taken by a Process Owner to identify, analyze and improve existing processes. |
Is Testing a QA or a QC Activity?
The difference is that QA is process oriented and QC is product oriented. Testing therefore is product oriented and is in the QC domain.“Testing for Quality” isn’t assuring quality, “It’s controlling Quality”.
Quality Assurance ensures you are doing the right things, the right way. Quality Control ensures the results of what you’ve done are what you expected.
Testing is a specific example of a Quality Control activity but it wouldn’t be accurate to assume they are one and the same. One example is stability testing of new drug substances or products. Or, it might include testing a sample for mean time to failure or service life. It’s a component of QC, but there are certainly others.
Even some huge western multinational corporations are not clear about the role of quality assurance (QA). Many think that quality assurance is the same as quality control (QC). QC is a business process, just like sales and production.
In meeting customer’s expectation, QC is merely in charge of the product quality but QA is to answer for process quality involving product quality, on time delivery, design requirement etc.
A QC person may stay idle after they have done all the product checking but a QA person will not have idle time at all because there is always something to improve. If anybody wants to associate QA with inspection, then QA is to inspect documentation. QA is not a business process. QA oversees all business processes from supplier’s quality to customer’s enquiry and from product realization further to after sales service.
very interesting, thanks