Both quality assurance (QA) and quality control (QC) area practices are aimed at ensuring quality of the finished product. In the AEC industry, those products happen to be buildings and other structures people use in everyday life. Despite being critical parts of a construction quality management program, professionals often use the two terms interchangeably or simply list them together as QA/QC in construction consulting companies’ service offerings.
However, quality assurance and quality control are distinctly different activities. Understanding this difference helps clarify the communication between project owners, contractors, and other stakeholders. A good understanding also helps project owners and managers build the right team of internal and third party construction quality consultants to meet the project’s quality goals. Conversely, a poor understanding can lead to decisions to forgo one or the other, increasing the risks of construction defects and other claims down the road.
What are QA and QC in a nutshell?
Quality assurance (QA) is a set of planned and systematic activities which are laid out before a building project starts. The aim of this activity plan is to give confidence that quality requirements will be fulfilled. To put it simply, quality assurance is planning to do the right things at the right time and the right way.
Quality control (QC) entails observation techniques and activities which aim to identify whether the final product actually fulfills customer requirements. Quality control also identifies the need for corrective measures. In other words, quality control monitors work as it happens and ensures that the results satisfy the requirements specified.
What are the key differences between QA and QC?
Quality assurance is about a plan. It’s carried out before the construction project starts. It’s a process that manages quality. QA lists the processes, standards, and policies that need to be carried out and ensures they’re known to the people who need to know them.
For example, when working on a building’s foundation, quality assurance is the outlined process of having someone check the rebar and forms, submit issues that need fixing to a private website, and make sure they’re fixed before concrete pouring begins.
The core of quality control are observation and corrective action activities. Even when you have the best plan and system in place (that’s what quality assurance does), you still need the right people (or in some cases, a programmed system) to monitor the work as it occurs to make sure the results are what you expect them to be. In plain-speak, QC is the inspection of the craftsmanship on a construction project. It verifies the quality of the output or takes action to help correct issues.
Going back to the foundation example, quality control will be the inspector visiting the construction site, checking that rebar is suspended at the right height, tied appropriately, and that the interior of the forms is free of debris.
What is quality in construction in the first place?
Both QA and QC are valuable practices to help ensure quality in construction workmanship. Quality is a measure of excellence in how well a product or service meets the client and end-user’s requirements and needs.
In new building construction, the end product is the completed structure and the surrounding property it sits on. A quality building is free from defects and significant shortcomings, adheres to the local building codes, measurable and verifiable standards, and achieves its performance goals and requirements.
Achieving this quality level in a project is a standard goal for construction professionals for many reasons. The first of which is the finished building becomes a standing example of their work that construction companies demonstrate their capability to future clients. A close second is that QA/QC helps manage the risks against unwanted results, like construction claims.
Quality assurance and quality control are different, but complementary parts of a larger concept – quality management. Achieving success in a building project requires both QA and QC. If either QA or QC are left out, it becomes near impossible to produce an effective construction quality program.
If you only lay out plans that define processes and procedures to be carried out (QA) but they aren’t followed by anybody qualified, those plans become little more than a paper making exercise. They may be great, but poor execution will still lead to lots of rework, change orders, and mistakes slipping through, only to later become construction defects.
On the other hand, if your inspectors conduct testing and observations to check the quality (QC) without a plan, you can miss the larger picture. The project can end up with inspection gaps or lack of follow-ups, and in the worst case, discovered mistakes can go undocumented and unaddressed. The project managers would also have trouble seeing underlying greater problems that needed timely addressing – creating risk of building failures that occur years after delivering the product.
Contact VERTEX for quality assurance services that set industry standards
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