“The primary focus of quality management is to meet customer requirements and to strive to exceed customer expectations,” according to the ISO, the International Organization for Standardization.

This means delivering as few errors as possible in a product that your customers find valuable.

Both quality assurance and quality control are key to achieving this. But often, the distinction between the two terms becomes blurred.

What is quality assurance?

Quality assurance (QA) is a formalized process of determining that a product or service meets specified requirements throughout the software development lifecycle (SDLC). It’s an approach that helps build confidence in a project’s outcome, as it establishes and maintains set requirements with the aim of improving the product’s efficiency, security, and reliability. Organizations who are successful at QA are often certified in the CMMI model and ISO9000 standards.

Quality assurance uses two key approaches – the defect management approach and the quality attributes approach.

The defect management approach tracks defects and categorizes their severity into the following:

  1. Critical
  2. Major
  3. Minor/ Moderate
  4. Low

Then there’s the quality attributes approach, which aims to achieve the following:

  • Functionality
  • Reliability
  • Usability
  • Efficiency
  • Maintainability
  • Portability

What is quality control?

Quality control (QC) is the set of procedures to ensure the product or service meets the defined quality criteria before distribution. While QA is the process of working to meet set quality criteria, QC refers to the inspection of the elements of the product or service. Essentially, QC validates that the QA processes were successful, or flags issues that QA missed.

During the development of an app, for instance, QA engineers will perform component integration testing. But perhaps all components aren’t fully developed yet, and as such, they must use stubs and drivers to simulate results. In an ideal world, the developers will phase these out and replace them with real components, which testers can check at the higher stages of integration testing. However, if they don’t replace them, the code could be prone to errors. Quality control is crucial in catching these oversights before they go to market.

But even with the most thorough and skilled QA team, QC is still necessary. QC engineers will inspect and test how the software works in a real-world scenario. It will then validate (or not) that the software conforms to its specifications, and that it does what the user requires. If they find that it doesn’t, they’ll apply fixes. At which point, QA should begin again.

Quality assurance vs quality control: what’s the difference?

Combined, QA and QC cover all bases. Let’s look at some of the differences between them that make this possible.

1. Goals

  • QA is proactive, aiming to prevent errors through testing and monitoring the design throughout the product development.
  • QC is reactive, inspecting and remediating any errors that slip through the cracks during the QA stage.

2. Focus

  • QA is process-oriented, focused on the planned activities involved in creating the software.
  • QC is product-oriented, focused on the software’s operational aspects and checking if it meets standards and requirements.

3. Processes

  • QA establishes guidelines and standards to meet requirements. It provides documentation of practices and audits performance throughout the SDLC. QA also involves training personnel so they can implement these processes.
  • QC involves inspecting and testing to validate the product’s safety and efficacy before distribution. This can include batch sampling, where engineers choose several products at random. And if they find any defects, QC also involves remediating them.

4. Responsibilities

  • QA concerns the whole organization. It requires everyone to follow the standard operating procedures (SOPs). As such, it requires stakeholder sign-off as well as staff learning and development to ensure its success.
  • QC involves a dedicated team. They follow SOPs for product testing and validation, and document their findings.

As such, any QC engineer worth their salt have will also have experience in QA, and accreditations too.

Quality you can rely on

“The cost of finding and fixing bugs or defects is the largest single expense element in the software lifecycle.” – The Cost of Poor Software Quality in the US: A 2020 Report

Quality assurance and quality control are very much intertwined. So, it makes sense to have one team do both. But the current skills shortage can make this seamless approach unachievable in-house.

At Success Software Solutions, our engineers know both QC and QA through experience and qualifications. They also hold certifications in ISO and CMMI standards, so they can help implement quality throughout the SDLC, and check the success of that implementation during the inspection stage.

But here’s the best bit. We specialize in offshore deployment, finding the right fit for your project with experts who integrate with your team and your timezone. So, that skills shortage everyone’s talking about – it need no longer affect you. Meaning projects delivered on time, at a lower total cost of ownership, to a standard that exceeds expectations.