What is the Difference Between Quality Assurance and Quality Control?

Ewa Rutczyńska-Jamróz
22 April 2022
7 min read

In a highly competitive market, rising interest in a new product or service can present gilded opportunities. Yet they are also opportunities easily squandered once that product or service fails to meet customer expectations and/or requirements. That is why quality assurance and quality control remain paramount for those well acquainted with the formula for success.

Although quality assurance and quality control are both parts of the quality management process, they are decidedly not the same. In this article, we'll explore the purposes of quality assurance and control and thereby clarify the differences between them.

Here we go!

Quality assurance vs quality control: definitions

A good starting point for explaining these two terms is ISO 9000. It refers to the quality management system which, according to Wikipedia "is a set of standards that helps organizations ensure they meet customer and other stakeholders' needs within statutory and regulatory requirements related to a product or service".

ISO 9000 standard includes the definitions of both quality assurance and quality control.

Based on these:

  • Quality assurance is a part of quality management focused on providing confidence that quality requirements will be fulfilled (clause 3.2.11)

  • Quality control is a part of quality management focused on fulfilling quality requirements (clause 3.2.10)

With this in mind, we can conclude that the main purpose of quality assurance is to focus on the process of quality while quality control focuses on the quality of output (i.e. the quality of a product or service).

But this is just one aspect. Let's have a closer look at both terms.

What is quality assurance QA?

QA is a set of procedures planned during the software development life cycle. Its ultimate goal is to ensure that the released product will be of the highest possible quality.

Every organization should establish QA procedures to see that each product meets its expected standards. Specific business norms and requirements should be taken into consideration (e.g. for medical products).

In practice, QA impacts numerous areas of the organization, including:

  • Setting requirements for a product or service

  • The design and prototyping stage

  • Code inspection

  • Release management

  • Customer satisfaction

  • Documentation and audits

What is quality control QC?

QC is a subset of quality assurance. It focuses on making sure that a product or service meets the quality standards, i.e. that they are free of potential defects (e.g. too low speed, design imperfection). Quality standards are based on business requirements as well as on customer expectations.

QC is done by a dedicated team that is responsible for:

  • Identifying defects

  • Product sampling

  • Software testing against quality standards

  • Laboratory testing

  • Identifying areas of improvement (e.g. user experience).

Quality assurance vs quality control: an example

To ensure a thorough understanding of QA and QC, let's have a look at the example of NASA.

This is how NASA defines QA: "Our quality assurance processes are designed to monitor, assess and improve work practices, and assist in getting everything right at all stages of a project from pre-planning to closure."

Their quality assurance process:

  • Is aimed at maintaining operational consistency, identifying uncertainties and opportunities for improvement

  • Includes performance monitoring, document/process reviews and assessments, safety oversights

  • Results in developing customized solutions, proactive eliminating problems, improving operational performance, assuring safety conditions for employees and cost optimization

Meanwhile, QC is defined by NASA as: "An aspect of the quality assurance process, our strong quality control program creates an environment in which our management and employees both strive for perfection. We earn our customers' trust by ensuring our products and services adhere to NASA and industry standards and meet our customer requirements."

Their quality control process:

  • Is aimed at ensuring satisfactory results for the customers and immediately detecting any new issues

  • Includes creating benchmarks for a product or service quality and examining products/materials in search of potential defects and improvements (e.g. materials testing, failure analysis, calibration services).

Quality assurance vs quality control: summary

In terms of defining QA and QC, let's summarize their most important aspects:

  • Both QA and QC are integral to the quality management system, however quality control is simultaneously a part of the quality assurance process.

  • Once quality assurance is part of the product development process with a defined goal of ensuring a high-quality product release, quality control then verifies that the developed product meets the standards of the organization (process vs product).

  • Although they may sound similar and have similar intentions, they are two terms that should not be used interchangeably.

Let's clarify further.

What is the difference between quality control and quality assurance?

Once we have explained what quality assurance means and what quality control stands for, it's time to elaborate on the differences between QA and QC.

No 1: Proactive vs reactive

QA is about setting a framework for the software development life cycle and includes the requirements and organization of workflow (e.g. programming, software testing). It focuses on determining how quality will be achieved throughout the process and on how to minimize the risk of errors.

QC is a reaction to a product that is already developed. It focuses on checking if it is free of bugs, i.e. whether it can be released to customers or requires further improvements.

No 2: Prevent vs fix

QA is used to structure the whole process of product development in such a way as to prevent errors. Such an approach enables limiting the number of defects before the products reach QC.

It significantly implies the capital intensity of the process. Thanks to the early detection of bugs, it makes it much easier and cheaper to implement any necessary improvements.

To sum up, the role of QA is to prevent, while the role of QC is to identify and fix any errors before the product is released to customers.

No 3: Who and when

QA is teamwork. It involves the cooperation of numerous departments within an organization, including business representatives, developers and testers. They must all agree on quality standards and then adhere to them throughout the procedure.

Once properly completed, the QC team is then involved to address any residual defects. To simplify, you could consider QA as pre-development during the testing stage and QC as post-development.

No 4: Process vs product

QA focuses on procedures that constitute grounds for the product development process. They involve not only setting the quality standards and requirements but also involve such activities as training, proper documentation, reporting, audits, etc. Clearly, a lengthy process.

QC team gets involved once the product is already developed. Their job is comparatively brief and incurs less cost owing to the fact that QA will already have identified the majority of existing defects. QC's prime focus will be on whether there are any further improvements that can be made to the product before it is engaged by the user.

QA and QC: similar but different

The reason for which QA and QC are often confused is that they share similar goals. In the end, it's all about detecting errors, providing the customer with a high-quality product, and optimizing [minimizing? - ed.] product development costs.

What's more, both concepts rely on procedures and standards that must be adhered to inflexibly, and also have a huge impact on the learning curve of the organization.

They create opportunities for improvements in many areas, including the development process and usability testing.

Despite these similarities, QA and QC remain different animals and are not to be confused with one another. At the same time, this doesn't mean that they should be considered in competitive terms. Neither has an advantage over the other; both are necessary to the organization for delivering value to clients and thereby securing the revenue stream.

Benefits of quality management

The main benefit of quality management to both QA and QC is the power to boost the company's quality improvement and thus reduce its corrective measures. This results in further benefits:

  • Early detection of errors

  • Fewer changes to the project

  • Reduced costs

  • Increased employee motivation and engagement

  • Increased inter-departmental cooperation

  • Quicker time to market

  • Positive impact on user experience and customer satisfaction

  • Minimized level of customer complaints

At Startup Development House, we just can not ignore all of these benefits while turning ideas into real-life products for our clients. As fixing bugs in production can be up to 30x more expensive than fixing them during the requirement and development stage, we engage our QA team in the project as soon as possible.

We strongly believe that QA and QC are inter-related aspects of superior quality management. We hold that these are key to equally superior product quality and customer satisfaction.

We also think that the best possible application of each is achieved only through a highly-experienced comprehension of their differences.

If you have an idea for an application or other digital product, contact us and together we'll develop it from scratch and according to the highest standards of quality.

Learn more about quality assurance in IT from our previous blog post.

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