FOOD SAFETY AND QUALITY ASSURANCE: QUALITY SYSTEMS
Diagram
How QA and QC work together
QA system: written steps, trained staff, set limits
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Production runs under those steps
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QC checks: sample, test, measure, decide pass or fail
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Results feed back: fix the step, update the QA plan
Figure 1: QA sets the system, production runs under it, QC checks the result, and the result feeds back into QA.
Introduction
QA and QC are two different jobs that a food factory needs at the same time. QC, quality control, is the checking part: it inspects, tests, and measures a lot and decides pass or fail. QA, quality assurance, is the system part: it writes the procedures, trains the staff, and audits the work so that good product comes out time after time. A short way to keep them apart: QC asks, is this lot good; QA asks, is our way of working able to make good lots again and again.
Table 1: Quick comparison of QA and QC
| Aspect | QA | QC |
|---|---|---|
| Full name | Quality assurance | Quality control |
| Question asked | Is our way of working able to make good lots again and again? | Is this lot good? |
| Focus | The process and the system | The product and the lot |
| Timing | Before and during production | Mostly after a step is done, on samples of the lot |
| Main work | Write procedures, train staff, set check schedules, audit | Inspect, test, measure, and decide pass, rework, or reject |
| Answer given | Confidence that the next lot should also be good | A decision about this lot: accept it, rework it, or reject it |
| Example | A manager writes the soup recipe with a salt range, trains cooks, and audits the weighing step each week | A worker tests the salt content of a soup sample and says pass or fail |
| Without the other | QA without QC is blind trust: the paperwork looks fine while bad product slips past | QC without QA is endless firefighting: every lot is a surprise |
Scientific explanation
Definition
Quality control (QC) is the checking part of quality work. It inspects, tests, and measures: a worker takes a sample of flour, tests its moisture, and says pass or fail, or an inspector looks at filled cans for dents and wrong labels. Quality assurance (QA) is the system part. It builds the rules so that good product comes out time after time: it writes the procedure for how flour is received, trains the staff, sets the oven check schedule, and audits whether people follow the written steps.
Working principle
QC works on the product, lot by lot, by sampling and testing against set values, such as moisture in percent or weight in grams, and then deciding the fate of that lot. QA works on the process, by writing what to do, how much, at what temperature, for how long, and what to record, and then checking that people follow it. When a QC check fails, QA asks why, fixes the cause, and checks that the fix held. That loop is the whole idea: checking feeds learning, and learning improves the system.
Apparatus
QC uses laboratory and inspection tools: balances, moisture testers, thermometers, and sieves. QA uses documents: procedures, training records, check schedules, and audit checklists.
Measurement procedure
A QC measurement follows a written method: take a fair sample, test it by the stated method, write the result, and compare it with the set limit. A QA audit follows a checklist: watch the step, read the records, talk to staff, and write down where practice differs from the procedure.
Factors affecting readings
A QC result changes with the sample, the method, and the instrument: a biased sample or an uncalibrated thermometer gives a wrong pass or fail. A QA result changes with training and with whether managers act on audit findings: a procedure nobody follows is paper only.
Formulas and calculations
This topic has no standard formula in the books used for this article, so no worked example is given here. Do not use a made up formula for this topic.
Industrial applications
- QA: writing procedures and specifications, training staff, supplier approval, internal audits, and management review in any food factory.
- QC: raw material testing on arrival, in process checks such as oven temperature and fill weight, and finished product testing before dispatch.
- Both: a biscuit factory uses QA to set the recipe and oven checks, and QC to test each lot of flour and each batch of biscuits.
Advantages and limitations
QA advantages: prevents faults instead of catching them late, and builds trust with buyers over time. QA limitations: it needs time, training, and honest audits, and it cannot prove a single lot is good without QC checks.
QC advantages: gives a clear pass or fail for each lot and catches faults before food ships. QC limitations: testing the finished food finds failures late, wastes food when a lot is rejected, and cannot test every unit, since some tests destroy the sample.
FAQ
Who owns quality in a factory?
Every person on the line, not only the laboratory. QA sets the system and QC checks the product, but production staff make quality happen.
Can a small business run QA?
Yes. A small business with ten workers can write short procedures, train staff, and check its steps. QA is not only for large factories.
If the food tastes fine but the label says the wrong weight, is that a quality problem?
Yes, it is a quality problem, and it can also be a legal problem, since the label must be true. QC should catch it before dispatch.
Which comes first, QA or QC?
QA sets the system first, then QC checks against it. But even the best system still tests samples at the end.
References and further reading
- FTN subject Food Quality Control and Standards, Unit 1: Introduction to Quality Control and Assurance System, sections 1.1 to 1.5.
- Book on disk: Food Quality Assurance: Principles and Practices.
- Google Books: Food and Drink: Good Manufacturing Practice, books.google.com/books?id=KugWswD7ESQC, for the GMP and quality system setting.
