What are the key differences between Quality Assurance (QA) and Quality Control (QC)?

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You’ve hit on a fundamental distinction! Think of Quality Assurance (QA) as the proactive "manager" of the system. It focuses on the processes used to create the product, such as audits, training, and process documentation, to prevent defects before they happen. Quality Control (QC) is the reactive "inspector." It focuses on identifying defects in the actual finished products through testing and inspection. In a Six Sigma framework, QA provides the standardized processes (SOPs) designed to stay within the $6\sigma$ limits, while QC provides the data (the actual defect rate) that tells the team if the process is actually performing as intended or if a "DMAIC" improvement cycle is needed.

   Answered 2025-02-15 by Emily Thompson

That makes sense for manufacturing, but how does this apply to Agile software development? In our Sprints, we don't really have a separate "QC" phase anymore because we test as we go.

   Answered 2025-02-17 by Michael Ross

• Hi Michael, in Agile, the lines definitely blur. We shift toward "Quality Engineering." The QA function becomes about setting up the automated testing pipelines and CI/CD gates (the process), while the execution of those tests acts as the QC (the product check). Even in Agile, you still need a QA mindset to ensure the "Definition of Done" is robust enough to prevent technical debt. The goal is to move the QC activity as far "left" as possible in the development lifecycle to catch bugs early, which is much cheaper than finding them in a final inspection phase.

     Commented 2025-02-19 by Emily Thompson

Use the PDCA (Plan-Do-Check-Act) cycle. QA is primarily involved in the 'Plan' and 'Act' stages, whereas QC is the 'Check' stage where the actual verification happens.

   Answered 2025-02-21 by Jessica Miller

• I love the PDCA reference, Jessica. It's the simplest way to visualize how quality is a continuous loop rather than a one-time event at the end of a project.

     Commented 2025-02-22 by Sarah Jenkins