Quality Assurance and Quality Control (QA/QC) on Site
Quality assurance is a system of procedures that prevents an error before it happens; quality control is the inspection and testing that verifies compliance after execution.
The difference between QA and QC
Quality assurance is preventive: plans, specifications, approved procedures, material approvals and training. Quality control is detective: inspecting work, taking samples, cube and density tests, and checking dimensions. The first reduces the number of errors and the second stops them passing, and relying on either alone leaves an expensive gap.
The approval cycle on site
Every material passes a material approval before delivery, and every activity passes an inspection request before it continues: no pour starts before the reinforcement and formwork are inspected, and no plaster starts before the buried services are checked. On many projects these requests being late or rejected holds the programme up more than a shortage of labour does.
The inspection and test plan (ITP)
A document that sets out for every activity: what is inspected, when, by whom, what the acceptance criterion is, and what record it produces. Preparing it before execution begins turns quality from a daily argument with the consultant into a procedure agreed in advance, and sharply reduces non-conformance reports.
The cost of quality against the cost of its absence
Prevention and inspection cost working days and laboratory fees; failure costs demolition, rebuilding, delay, damages and lost trust. Quality is the one budget line whose reduction saves imaginary money and costs real money.
Worked example
On an apartment project the consultant refused a slab pour after an inspection found insufficient concrete cover to the reinforcement. Correcting it took one day; discovering it after the pour would have meant a structural remedy to a whole slab costing over SAR 200,000 and weeks of delay.
FAQ
What is a non-conformance report (NCR) and when is it issued?
It is issued when work has been carried out contrary to the specification, and states the non-conformity, the corrective action and its deadline. An accumulation of NCRs indicates a fault in the prevention system, not merely individual errors.
Does a small project need a quality system?
It needs a simplified version: a checklist for each principal activity, a material receipt record, and concrete test results. Size changes the amount of paperwork, not the principle of verification.
Who pays for re-testing?
The principle is that the contractor bears it where the retest is caused by its own non-conformity — a clause worth stating in the contract to avoid an argument at the first failed test.
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