Quality Control vs Quality Assurance
Since we are in to Quality Management for construction projects, many a times we had to explain about the above subject. So just thought of bringing it on record of some our thoughts on the subject…
Quality Control (QC): Comparing the results of Checking / Inspecting / Testing (CIT) process with the standards.
Ex: Ponding test for bore packing
Quality Assurance (QA): Taking all the necessary steps to get positive outcome from QC procedure.
Ex: Laying out the methodology, supervision & checking mechanism so that the Ponding test will be passed
Purposefully I have taken up the Ponding test for explaining QA/QC – main reason is many people in our industry think that QA/QC process starts and ends with site laboratory. But QA/QC process is actually involved in every part of construction activities and not stopped only with incoming material testing.
There are various outputs for every processes followed. These outputs should fulfill certain criteria so that next process can be taken up. The process of CIT (Checking/Inspecting/Testing) the outputs to see that these outputs fulfill the required criteria is called as Quality Control.
Ex: Checking the incoming materials for further processing, Inspecting shuttering system for permitting concreting, checking the plastering finish and curing time to permit painting process to start
Scope of Quality Assurance is very big. Quality Control is a very small part of Quality Assurance. That is, deciding on which material to use, setting the methods of checking and fixing requirement criteria, deciding the proper methodology, implementing required processes to ensure the supervision, etc., are part of Quality Assurance.
Ex: Setting up Method statements, Laboratory manuals, Checklists, reporting formats, implementing control mechanism, etc.,
The below picture is the representation of above discussion:
Generally in many company’s evolution, Quality Control takes up the initial period since many standards (BIS, Euro, ISO, ASTM) are readily available. Quality Assurance will evolve out of it. After certain stage Quality Assurance takes up the major role.