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    Quality ControlQC

    Also known as: Quality checks

    Definition

    The checks, such as sampling, inspection and testing, that confirm a product or service meets its requirements, and the action taken when it does not.

    Editorial definition: The QHSE Standard, updated 3 October 2026 · https://qhsetech.com/glossary/quality-control

    Scope: QC is one part of a quality management system, not the whole of it. Definitions differ by sector, and WHO's wording is written for medicines.

    Example for your evaluation: Follow one failed check from the sampling record to the nonconformance, the held material and the decision to release or rework it.

    Sources checked: . Examples are editorial illustrations.

    How WHO defines quality control, and how it sits beside QA and a QMS

    Quality control, usually shortened to QC, is defined by WHO in its 2010 good practices for pharmaceutical quality control labs (Technical Report Series 957, Annex 1). Its glossary describes QC as all measures taken, including setting specifications, sampling, testing and analytical clearance, so that materials and finished products conform with established specifications for identity, strength, purity and other characteristics. The wording is written for medicines. Other sectors use their own wording, and ISO 9000 and ASQ's page on quality assurance and quality control could not be opened for this page, so they are not restated.

    The same glossary separates QC from the wider system. It describes a quality management system as the infrastructure (structure, procedures, processes and resources) and the systematic actions needed to give adequate confidence that a product or service will satisfy quality requirements. It calls good manufacturing practice that part of quality assurance which ensures products are consistently produced and controlled to suit their use, and a quality unit an organisational unit, independent of production, that carries both quality assurance and quality control duties. On this page's own summary, not WHO's wording, QC is the checks and decisions about particular materials and the QMS is the structure that governs how they are planned, documented, audited and improved.

    WHO's texts also show what QC leaves behind. Its sampling guidelines (Technical Report Series 929, Annex 4, 2005) define a sampling plan as the location, number of units and quantity to collect with the acceptance criteria, and a sampling record as a written record holding the batch number, date and place, the protocol used, the containers and material, any abnormalities and the inspector's signature. The lab guidance says test results should be reviewed and, where appropriate, evaluated statistically, doubtful results investigated, all individual results reported with acceptance criteria, and conclusions signed by a supervisor. This page is general information, not regulatory advice, and a rule written for medicines does not carry over to other products.

    Sources opened :

    What a quality control record holds in software

    • The specification or acceptance criteria, with the revision they came from.
    • The sampling plan and sampling record: what was taken, from which batch, where, when and by whom.
    • The inspection or test record: method, equipment identifier and calibration status, who performed it, the raw data and every individual result.
    • The evaluation against the criteria, the decision (accept, reject or hold) and the reviewer's signature.
    • An out-of-specification or nonconformance record for any result outside the criteria, with the investigation, any retest and its justification, and what happened to the material.
    • Control chart data, where the site charts a characteristic over time: the points, the limits and who set them, and the action at a signal. WHO's lab guidance mentions control charts as one source for estimating measurement uncertainty.

    QC, QA, QMS and inspection

    Inspection and testing are activities inside QC. WHO's 2010 glossary does not define quality assurance on its own; it places good manufacturing practice as a part of it and gives its quality unit both duties. A site can inspect everything and still lack a management system. The quality manual WHO describes for a control lab lists policies for audit, corrective and preventive action, complaints, management review and out-of-specification results. A nonconformance raised from a failed check belongs to the QC workflow, and the corrective action that follows sits in the wider system.

    A hypothetical example: a fill-weight check that finds one low bottle

    This case is invented to illustrate the record and describes no real company. A bottling line has a specification of 500 g with limits of 495 g to 505 g. Each hour an operator weighs 5 bottles and records every weight and the scale's calibration date. At 08:00, 09:00 and 10:00 the mean weights are 500.4 g, 501.2 g and 502.0 g. At 11:00 the weights are 499, 501, 494, 500 and 502 g, a mean of 499.2 g, and the 494 g bottle is below the lower limit.

    The operator opens a nonconformance record. The line stops, the 1,200 bottles filled since the 10:00 check are held, and the scale's calibration is verified before anything is retested. The cause is a worn valve on one filling head, so the result stands. All held bottles are weighed: 37 are below 495 g and are reworked, and the other 1,163 are released. The site's invented rule is to review the chart when three consecutive means rise, which the 08:00 to 10:00 means had done, so the maintenance note links to the same record.

    Common misunderstandings about quality control

    • QC is not the quality management system. Checks are one part of it, and the system also covers procedures, audit, review and corrective action.
    • A passed check is not the whole record. WHO's lab text asks for all individual results, not only the passes.
    • Retesting until a result passes is not what WHO describes. A doubtful result can be rejected only if clearly due to an identified error.
    • WHO's wording is for pharmaceutical products. Use the standard or customer requirement that applies to your product.
    • QC and QA need not be separate teams. WHO's quality unit can be one person or group depending on size, though it is independent of production.

    How quality control relates to other glossary terms

    Quality control produces the results. These terms cover what happens next and the system around it.

    • Non-conformance: the record raised when a check finds a result outside its requirement.
    • CAPA: the process that deals with the cause when correcting one batch is not enough.
    • ISO 9001: the quality management system standard, covering the system around QC checks.
    • SOP: the written procedure behind each sampling, test and out-of-specification step.

    Records and evidence that usually exist for quality control

    • Specifications and acceptance criteria with their revision history.
    • Sampling records signed by the person who took the sample.
    • Inspection and test records with raw data, equipment identifiers and calibration status.
    • Review and sign-off of results by a named second person.
    • Out-of-specification and nonconformance records with the investigation, retest justification and disposition.
    • Control charts and the action taken on each signal, where charts are used.

    What a software tool needs to capture for quality control

    • Acceptance criteria held as versioned data, so each result is compared with the revision in force.
    • Sampling plans that create the sampling record fields, such as batch, location, time and sampler.
    • Every result kept, including failed and repeated ones, never overwritten.
    • A hold or block on release when a result is outside the criteria, with any override recorded.
    • A link from a failed result to a nonconformance record and on to any corrective action.
    • Calibration status of the equipment shown at the time of the test.
    • Review by a named second person, with a timestamp that cannot be silently edited.

    Catalog profiles documenting quality inspection workflows

    Listed profiles meet the quality inspection rule. Nothing here shows that a product holds control charts or sampling plans, so ask for a worked sample in a demonstration.

    Same rule for every product: tagged “Quality Inspection”, “Quality Inspections”, “Inspection Management”, “Manufacturing Quality”, “First Article Inspection”, “Statistical Process Control (SPC)”, “SPC” or “Quality Management”, with a sourced quality inspection or sampling capability in its record, or one the vendor stated to us, labelled as vendor-stated. Documented and conditional capabilities qualify; check the linked scope before treating a module as included.

    Tekmon pays for a sponsored placement (above); its place in this list follows the same rule as every entry. How lists are ordered

    All 7 matching profiles are shown. Documentation review, not hands-on testing or a claim of compliance.

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    Frequently asked questions

    Is quality control the same as quality assurance?

    Not quite. WHO's 2010 glossary defines quality control as the measures that confirm materials and products meet specification and calls good manufacturing practice part of quality assurance. One quality unit can hold both.

    What records does quality control produce?

    Specifications, sampling records, inspection or test results, reviews, out-of-specification investigations and, where used, control charts. WHO's lab guidance describes most of these for medicines.

    What should happen when a result is out of specification?

    WHO's lab text asks for the doubtful result to be investigated before any retest, with the investigation recorded and the number of retests set by procedure. Other sectors set their own rules.

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