Quality Assurance vs. Quality Control 1

[johnsmith8]

I work for a testing company as an inspector. I seen the terms "quality assurance" and "quality control" were use loosely in specs book. Can someone tell me what are the diffence between those two terms and how they apply? thanks

 

[DMcGrath]

They way it has been explained to me is QC is "we did the required testing at the required frequency". QA is "The testing was done, we've examined the results and we say it meets the project specifications".

 

[Ron]

johnsmith8...there are essentially 3 levels of quality engagement.

Quality control can only be done by the person actually doing the work. After all, he/she "controls" how well they perform a task. Testing labs and inspectors are not in the Quality Control business, though they sometimes say they are (if they knew anything about liability and exposure, they wouldn't use the term to describe their business).

The next level is Quality Assurance. This is done by someone who has supervisory capacity over the person doing the work and can decide on means, methods, and materials. Quality Assurance may or may not include some testing function. Testing labs and inspectors can assist in this level.

The final level is Quality Verification or Validation. This is done as a check on the other two and is done by someone completely independent of the work operation, such as an inspector or testing laboratory.

 

[henri2]

For building construction, the testing lab does QA, while the contractor is responsible for QC as Ron has stated. See IBC-03 Sections 1705 and 1706. In fact, in special inspection seminars offered by ICC staff, they take the position that the QA team comprises: bldg dept inspectors-Sec 109, special inspectors-Sec 1704, and structural observers - Sec 1709. I understand the QAP provisions in the 06 code are now included with the statement of special inspections.

http://www.structuremag.org/archives/2006/July-2006/C-Insights-Inspections-Schindler-July-06.pdf

For many public works projects, independent testing labs are hired by contractors for C-QC (contractor quality control). On the other hand, working for the contractor is considered a conflict of interest under the International Bldg Code.

 

[irasamm]

The posts above show the definition of each varies for different projects. Check contract documents/agreements or your management, not your specs, for the answer and how it applies to your task.

 

[BigH]

Ron - I beg to differ slightly with your much learned opinion. I agree that the QC is the contractor's responsibility - but he may hire a testing laboratory/inspecting company to do the work for him; so testing laboratories may be in the business of QC but as a subcontractor/subconsultant (if you prefer) to the contractor.
You are correct, as I view it, on the QA in that this group oversees the work and confirms overall compliance with the QC programme. Typically, this group is or should be independent of both the contractor and the client - and even the EOR. On my job, we will be doing independent QA testing of the same "batch" that the contractor does - but at a frequency of say 15% or so of the QC programme. We consider this to be the verification of the Contractor's QC work for acceptance testing results - an independent outsider wouldn't be brought in unless there were/are issues.
Boy, I hope I understand this correctly! - and it does get confusing in that QC and QA really are 'loosely' used as the original poster indicated - you see "QC/QA Manager" used quite a bit - how can a person be both the manager of QC and QA on a job???

 

[mitchelon]

I agree with irasamm. Check your contract documents.
BigH – I believe Ron provided the universal descriptions for QA/QC. QC is a process that starts before the actual construction takes place. Labs could be hired to do QC to some extent, but they would still be working for the GC and the customer doesn’t care how the GC controls quality as long as they do. Legally, the GC is responsible for quality and if the hired lab failed, that is between the lab and the GC. Again, GC’s can hire labs as consultants, but overall labs mostly do testing.

 

[LCruiser]

QC is checking doing things right.
QA is checking doing the right things.