Builders often refer to their construction quality programs as “QC - Quality Control” and “QA - Quality Assurance.” Obviously, both terms target “quality,” but are they interchangeable? And if not, what’s the difference?
QA vs QC - The difference explained
Quality Assurance (QA) and Quality Control (QC) in construction are actually separate concepts (or levels) of one system. Boiling it down to the basics, Quality Assurance is process to achieve a quality product, and QC is the execution of that plan.
Quality Assurance is strategic. It’s the designed and sequential activities that make up a system to measure the output of a product or service against an established standard. Put simply, QA is about understanding what’s required to achieve quality, and creating a system to carry out those requirements.
QA is, for example, a series of checklists and inspections set at critical stages in the construction schedule, such as a Pre-Pour, Frame, Pre-Drywall and Final Delivery.
Together these points make-up a system that ensures construction is complete and accurate in one phase before the schedule continues to the next phase.
There is an end goal in mind to build the project on schedule which prevents defects and has overall fewer errors and rework.
Quality Control is tactical. It’s the act of monitoring the work as it occurs. QC ensures that material installation and the activity completion conform to the builder’s expected standards.
QC also implements corrective measures when those standards aren’t met.
QC happens on the jobsite and requires the quality managers, field supervision, and contractors to use the QA tools. For example: Before the framing crew begins their work, they review a Hot Spot photo to avoid a recurring mistake.
Then, before they leave the jobsite, the crew leader follows a checklist to ensure all items are complete and no callback will be required. Finally, the Contractor completes a framing inspection before allowing the HVAC crews to begin their work. There is no planning involved, just execution.
Both parts – the planning and the execution – are essential to deliver a quality project. But with most builders, a great deal of time and detail are invested in creating a comprehensive Quality Assurance Program, only to have it fall apart at execution.
The daily grind of the jobsite overrides the task of completing checklists and performing inspections, and Quality Control goes by the wayside. Thus recurring errors continue, callbacks waste more time and money, and the quality of the end product suffers.