by Renaud Anjoran in 'Quality Inspection Blog'

I often have to explain what the difference between quality assurance (QA) and quality control (QC) is. The best is for me to write an article about it, and I’ll point people to it in the future.

Here is a short version:

QA = all the activities that aim at ensuring a certain level of quality. It includes defining what the requirement are + setting up a proper management system + QC.

QC = only the activities that consist of checking whether conformity is achieved or not. In the context of an importer who needs to secure his product quality, QC means checking if the specs are respected in production, and it translates into 2 types of activities: on-site inspections (statistical quality control) & laboratory testing (only on a few samples taken out of bulk production).

Here is the more detailed version:

1. Good QA takes time but is worth it

For an importer buying finished products from low-cost Asia, QA includes the following steps:

• Making sure the design is “manufacturing-friendly” and will not cause defects
• Auditing and approving factories based on a relevant checklist
• Getting the manufacturer’s approval of the quality control plan
• Writing down detailed product specifications, and getting the manufacturer’s approval
• Identifying failure points with production engineers, and removing them (back to design)
• Following pre-production sampling closely, and if possible launching a pilot run
• Ensuring that lessons from sampling will be taken into account for production
• Performing QC at one or several points of mass production
• Following up with corrective/preventive action plans, when applicable
• Re-engineering production processes (to reduce opportunities for errors)
• Revising product specifications for the next production batch

2. QC is part of QA

It is important to understand that QA includes QC. It is not “either QA or QC”. Good QA is dependent on QC, since the information from inspection is necessary to implement corrective and preventive measures.

The old way: inspect bad quality out; The new way: build quality in.

- W. Edward Deming

3. QA is constantly mixed up with QC

“QA” and “QC” are often used interchangeably. “QA” sound smarter than “QC”, so QA is frequently substituted to QC. I have met with “QA technicians” who actually do statistical quality control every day.

Have I left anything important out of this article?

Renaud Anjoran is the founder of Sofeast Quality Control and helps importers to improve and secure their product quality in China. He writes advice for importers on the Quality Inspection blog. He lives full time in Shenzhen, China. You can contact him at info@sofeast.com.