One of the most frequently asked questions on the Internet and during interviews – What is the difference between Quality Assurance and Quality Control?
Quality Assurance and Quality Control are the two terms that are often used interchangeably, however, there are distinct differences between them. Sometimes, even some of the professionals lack clarity when asked about the difference between QA and QC. Today, we will be looking at QA vs QC and try to clear this confusion so that you have a better idea and understanding of these two concepts.
Quality Assurance and Quality Control are the two facets of Quality Management that ensure quality standards in a product are achieved during its development process and post-production. The ultimate output of both is to deliver a quality product. Although some activities in both are interrelated, they are perceived differently. Let’s take a look at the two terminologies individually.
As per ISO, Quality Assurance or QA is an aspect of Quality Management that focuses on providing confidence that quality requirements would be achieved. It can be defined as a set of activities performed during the product development process to ensure quality and prevent any errors or identify flaws in the process. Put simply, these activities determine the process and standards to develop a software product and ensure they are correctly implemented.
The other aspect of Quality Management, i.e. Quality Control or QC tends to focus on fulfilling quality requirements. Speaking from the perspective of Software Testing, QC refers to the set of activities that helps ensure quality in the product (and not the process). Quality Control is about identifying defects in the final product or software developed. An alternate way to define QC is that it observes and verifies that the project deliverables match the desired or defined quality standards. QC can also be called a subset of QA.
The primary difference between QA and QC is that the former is more about maintaining quality while assessing the process whereas the latter relates to inspecting quality in the product produced. We have compiled a list of a few other factors as well that would clear the ambiguity around Quality Assurance vs Quality Control.
QA is a proactive quality process- the objective is to prevent defects with a primary focus “on the process” used to develop the software or the product. It involves the prevention of quality problems through planned and systematic activities including documentation that comprises Failure Modes and Effect Analysis, Standard Operating Procedure(SOP), Work Instructions, Control Plan, etc. to assure quality during development.
QC, on the other hand, is a reactive process as it is directed towards identifying and correcting defects, bugs, or any errors “in the finished product.” It involves techniques that are leveraged to achieve and maintain the software quality after it is developed.
The goal of Quality Assurance is to improve or enhance the quality of software development or test processes so that defects don’t arise when the software is being developed. It tends to eliminate defects during the development phase. Product verification is an example of QA.
Conversely, the goal of Quality Control is to identify or pinpoint defects after the software is released but hasn’t been launched. Product validation or software testing is an example of QC.
Another difference between QA and QC is of approach. The approach behind Quality Assurance is to set up a high-quality management system and check its adequacy, i.e. to audit its performance periodically. Different types of audits are performed such as product audit, process audits, and system audits. In Quality Control, the approach is to find and eliminate the sources of defects in the developed software through various tools and equipment so that customers’ requirements are constantly met.
Responsibility is yet another factor to consider when speaking of QA vs QC. When we talk about the responsibility factor in QA, everyone in the development team is responsible for it. People from different departments play their roles, be it the engineering, maintenance, or quality department. Generally, a cross-functional team is employed to implement the process so that QA remains maintained.
As far as Quality Control is concerned, there is a specific testing team assigned for that purpose that is held responsible to test the final software, identify defects, and make necessary improvements or corrections.
Statistical tools and techniques are used in both Quality Assurance and Quality Control but there is a difference as to where they are applied. In QA, they are applied to the processes (process inputs and operational parameters, also technically called Critical to Quality(CTQs) and Critical to Process(CTPs)). The statistical techniques used to manage these processes are called Statistical Process Control(SPC).
On the other hand, in QC, statistical tools and techniques are applied to the finished product or software (process outputs), and they are called Statistical Quality Control(SQC).
QA is a managerial tool while QC is a corrective tool. In QA, the senior management or managers from different departments are involved in system building, process designing, and development so that QA is maintained.
In QC, once the problems are detected in the software, they are analyzed and rectified.
There are many other ways to explain the difference between QA and QC. For instance, QA involves planning to correctly perform a process while QC involves actions required to execute the planned process. With QA, you make sure that you are doing the right things whereas, with QC, you make sure that the results achieved are as per the expectations. QA is to create the deliverables and is responsible for the complete software development cycle while QC is to verify the deliverables and is responsible solely for the software testing life cycle. Lastly, QA is process-oriented while QC is product-oriented.
Hope this clears everything around Quality Assurance vs Quality Control. Dew Solutions specializes in QA and QC. We have a pool of talented and experienced developers who ensure that product development is flawless. And our testers test your product at various levels to ensure that your product remains bug-free. If you require QA services for your project, do reach out to us at firstname.lastname@example.org or contact us here.
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