Quality Control in Manufacturing

This topic is part of the SG Systems Global quality control, testing, release & traceability glossary for regulated batch, discrete & hybrid manufacturing.

Updated December 2025 • Quality Control (QC) Testing & Release Evidence, Quality Management System (QMS), In-Process Control Checks (IPC), GMP Sampling Plans, Out of Specification (OOS), Statistical Process Control (SPC), Batch Manufacturing Record (BMR), Device History Record (DHR), Quality Risk Management (QRM), MES

Quality control in manufacturing is the set of activities that stops “we think it’s fine” from being your release strategy. It’s the discipline of deciding what “good” looks like, sampling and testing material and product against that definition, reacting when results drift, and documenting the evidence in a way that regulators, customers and your own future self can trust. Done well, QC is not just a lab at the end of the process – it’s baked into raw material intake, in-process checks, SPC, release decisions and stability monitoring. Done badly, QC is a bottleneck that rubber-stamps product based on habit and gut feel, and only becomes visible when a complaint, recall or inspection forces you to dig into what actually passed through the plant.

“If the only proof that the batch met spec is ‘we’ve never had a problem before’, you don’t have quality control – you have optimism with a COA stapled to it.”

1) What Is Quality Control in Manufacturing?

Quality control (QC) is the set of checks, tests and inspections used to verify that materials, intermediates, and finished goods meet specified requirements. It answers three blunt questions, every day:

• Does this lot meet the spec? – chemistry, microbiology, dimensions, appearance, function, label, packaging.
• Can we release it? – to the next stage, to packaging, to the warehouse, to the customer.
• If not, what do we do with it? – reject, rework, downgrade, investigate, escalate.

In regulated sectors (pharma, medical devices, food, cosmetics), QC is defined explicitly in regulations and standards. Labs, line inspectors and automated systems all count as QC when they generate data used for release decisions. QC isn’t just the lab in the basement; it’s every step where you determine whether reality matches what the drawing, the formula, the spec and the marketing claim promised.

2) Quality Control vs Quality Assurance vs QMS

Three terms get blended in conversation: QC, QA and QMS. They overlap but do different jobs:

• Quality Control (QC) – tests, checks and inspections on materials, processes and product. Data-driven “does this batch/lot/unit meet requirements?”
• Quality Assurance (QA) – systems, procedures and oversight that ensure the right processes are in place and followed (change control, deviation management, validation, training, audits).
• Quality Management System (QMS) – the overall framework that holds QC and QA together: policies, processes, organisational structure and digital systems. See QMS.

Put brutally: QC measures, QA worries, the QMS organises. You need all three. A plant with strong QC but weak QA and QMS can detect problems but keeps making them. A plant with a beautiful QMS but weak QC generates immaculate documentation about product nobody has really tested.

3) Core Elements of Quality Control in Manufacturing

Regardless of sector, quality control usually covers five building blocks:

• 1. Incoming material control – verifying raw materials, components and packaging against specifications.
• 2. In-process control checks (IPCs) – monitoring critical attributes during manufacturing, not just at the end.
• 3. Final inspection & release testing – deciding if finished product can be released based on tests and records.
• 4. Stability, shelf-life & re-testing – confirming product remains in spec over its stated life.
• 5. Complaint & field failure support – using QC tools to help discover what went wrong after release.

3.1 Incoming Material Quality Control

Everything downstream is easier if inputs are under control. Typical QC on incoming materials includes:

• Identity testing & verification – making sure the material is what the label and CoA claim.
• Assay / potency – in pharma and supplements, confirming active strength before use.
• Physical and functional checks – dimensions, colour, viscosity, hardness, performance tests.
• Microbiological tests – where relevant for food, cosmetics, sterile or low-bioburden products.
• Documentation checks – CoAs, safety data sheets, regulatory statements, change notifications.

Effective incoming QC is risk-based: not every bolt or carton gets tested, but critical or high-risk materials are not allowed anywhere near production without adequate checks.

3.2 In-Process Control Checks (IPCs)

In-process controls are where QC stops being a gate at the end and becomes a steering wheel during manufacturing. Examples:

• Granulation moisture, blend uniformity, pH, viscosity or torque readings mid-batch.
• Tablet weight, thickness and hardness checks at defined frequencies.
• Torque, gap or alignment checks in assembly operations.
• Fill-weight control on packaging lines.
• Visual inspections for defects, colour, cleanliness or assembly completeness.

IPCs are where SPC, trending and control charts come into play: you watch the process, not just the final result, and act when things drift, not only when they fail outright.

3.3 Final QC, Release Testing & Evidence

Final QC is the last controlled chance to say “no” before product leaves your control. It normally involves:

• Sampling & testing against finished product specifications – identity, potency, impurities, micro, appearance, function, label and pack checks.
• Review of manufacturing documentation – BMR, DHR, deviations, nonconformances, rework records and line checks.
• Release decision – formal QA sign-off, often under batch certification or QP/QP-equivalent responsibility.
• Evidence archiving – storing test results, chromatograms, forms and electronic records for the retention period.

Quality control is not just “test results”; it is the combination of test results plus documented evidence that the process was under control and any deviations were assessed properly before release.

3.4 Stability, Shelf-Life & Re-Testing

QC also protects the tail of the product life:

• Stability studies to support initial shelf-life claims.
• Ongoing stability / periodic verification.
• Re-testing of materials with “re-test by” dates.
• Monitoring of trends that might indicate slow drift (for example, potency loss, micro growth, packaging degradation).

This part of QC is less glamorous and often under-resourced until a stability failure forces a recall or product withdrawal. It’s cheaper to take it seriously up front.

4) Sampling Plans, SPC and OOS in QC

Quality control in manufacturing is not “test everything, all the time”. It relies heavily on statistics, trends and disciplined handling of bad news.

4.1 Sampling Plans

Sampling plans define how you select units or samples to test and how you interpret results. For example:

• How many samples per batch, per hopper, per lot, per hour?
• Acceptance numbers – how many defects are allowed before you reject?
• Different plans for critical, major and minor defects.
• Switching rules for tightened or reduced inspection based on past performance.

Good QC policies are explicit about sampling, not “we grab a few and see what they look like”. The more critical the attribute, the more rigorous – or continuous – the sampling method should be.

4.2 Statistical Process Control (SPC)

SPC is QC’s early-warning system. Instead of only asking “is this in spec?”, SPC asks “is this process behaving consistently?”:

• Control charts for weights, dimensions, potency, yields, micro counts, etc.
• Rules for reacting to trends and patterns before spec limits are breached.
• Linking process shifts back to change events, maintenance, raw materials or operators.

Where QC without SPC is a gate, QC with SPC is a steering wheel. It lets you correct quietly and early instead of waiting for spectacular failures.

4.3 Out of Specification (OOS) Handling

Even with good design and control, some results will fall out of specification. How you react sends a clear signal about your quality culture:

• OOS triggers formal investigation, not instant re-test until you “get a pass”.
• Analytical and manufacturing causes are considered separately – did the test fail, or did the batch fail?
• Decisions on batch disposition are documented and justified, not guessed.
• Patterns of OOS across products or labs feed into CAPA and method/process improvements.

In regulated industries, OOS handling is often one of the first things inspectors look at when judging whether your QC is real or cosmetic.

5) Quality Control in Different Manufacturing Sectors

The principles are stable; the emphasis shifts by industry.

• Pharma & biologics: Strong focus on potency, impurities, micro, sterility, particulate matter and stability; QC heavily lab-centred and tightly linked to GxP documentation and validation.
• Dietary supplements & nutraceuticals: QC often battles variable raw materials, label claim accuracy and micro/allergen control, with significant emphasis on identity and strength.
• Food & beverage: QC blends lab testing with sensory evaluation, on-line checks and micro, within HACCP and GFSI frameworks; speed vs robustness is a constant tension.
• Medical devices: QC includes dimensional inspection, functional testing, cleanliness/bioburden and packaging/UDI verification, feeding heavily into DHRs.
• Cosmetics & personal care: QC deals with stability, micro, rheology, colour, odour and claims; often under both cosmetic and quasi-drug regimes depending on market.
• Plastics, chemicals & agrochemicals: QC focuses on composition, physical properties, performance tests, impurities and, for agrochemicals, actives and co-formulants vs label.

What changes sector to sector is the test menu and regulatory wrapper. The core QC questions – “what does good look like?”, “how do we prove we hit it?” and “what do we do when we didn’t?” – stay the same.

6) Common Failure Modes in Quality Control

QC problems rarely start with the instruments. They usually start upstream in expectations and behaviour:

• Spec confusion: Operators, planners and QC use different, sometimes outdated versions of specifications; nobody is quite sure which one is “real”.
• Sampling theatre: Samples are technically taken, but not according to plan (for example, always from the top of a bin, always at the same time) – giving a comforting but misleading picture.
• “Test to pass” culture: Failing results quietly re-tested until something lands just inside spec, with no proper OOS investigation.
• Data silos: QC results live in LIMS or spreadsheets; MES, WMS and ERP never see them in time to act.
• Excessive reliance on end-product tests: Little or no in-process control, so failures are discovered late and expensively.
• Weak linkage to nonconformance & CAPA: QC keeps finding the same issues; the system keeps treating them as isolated accidents.
• No feedback loop: QC data is not used for design improvement, supplier management or process tuning – only for yes/no release decisions.

A QC function that only ever says “pass” and never triggers meaningful investigation or improvement is a cost centre, not a risk-control mechanism.

7) What Quality Control in Manufacturing Means for V5

In the V5 architecture, quality control is not just a lab or an after-the-fact report; it’s a connected part of how orders run, materials move and batches are released.

• V5 Solution Overview – treats QC results, checks and exceptions as native data objects linked to batches, jobs, materials, equipment and customers, not as external attachments.
• V5 MES – Manufacturing Execution System:
  • Drives in-process control checks through digital work instructions – prompting operators for samples, measurements and decisions at the right steps.
  • Captures QC data in structured form at the line, with limits, SPC rules and automatic triggers for holds or deviations when thresholds are breached.
  • Feeds QC events and results into electronic BMRs and DHRs, so release reviewers see the full picture without trawling through paper or separate systems.
• V5 WMS – Warehouse Management System:
  • Implements QC statuses and quarantine locations for incoming materials, WIP and finished goods – “awaiting test”, “on hold”, “released”, “rejected”.
  • Uses genealogy to link QC results to specific lots, pallets or serialised units – ensuring that dispositions are correctly applied to inventory and shipments.
  • Supports FEFO, shelf-life and stability rules by combining QC, expiry and storage conditions in one model.
• V5 QMS – Quality Management System:
  • Holds QC-related specifications, sampling plans and test methods under document and change control.
  • Manages OOS, nonconformances and deviations arising from QC results, linking them to CAPA, risk registers and change control.
  • Supports trending and review of QC performance as part of management review, APR/PQR and continuous improvement programmes.
• V5 Connect API:
  • Integrates external LIMS, test equipment and specialist labs, so QC results flow into V5 in real time instead of arriving as static PDFs or emails.
  • Exposes QC status and release information to ERP, customer portals and regulatory reporting tools where appropriate.

In a V5-driven operation, quality control stops being “the lab” and becomes a distributed, digital network of checks and decisions tied directly into how work orders, materials and releases are managed day-to-day.

8) Implementation Roadmap & Practice Tips

Strengthening quality control in manufacturing is usually less about buying new instruments and more about connecting and sharpening what you already do. A pragmatic roadmap:

• 1. Map your current QC chain. For one key product family, map every QC touchpoint – incoming checks, IPCs, lab tests, inspections, release decisions, complaint handling. Include who does them, where data is stored and how results flow (or don’t).
• 2. Clarify specifications & sampling plans. Make sure everyone is using the same specs and sampling rules, and that they are realistic, risk-based and documented. Retire duplicate or obsolete versions.
• 3. Move critical IPCs into MES. Use V5 MES and digital work instructions to drive critical in-process checks at the line, with clear limits and automatic escalation for out-of-trend or out-of-spec results.
• 4. Integrate lab results. If LIMS is separate, use V5 Connect to pull structured results into V5 rather than relying on PDF attachments. Tie those results to batches, lots and inventory statuses.
• 5. Tighten OOS and deviation links. Make it impossible for OOS or failed checks to disappear. Ensure every OOS or critical QC failure automatically spawns an investigation and, where justified, CAPA.
• 6. Build simple SPC where it matters. Start with one or two critical parameters and implement basic SPC charts and rules in V5 to catch drift earlier. Expand once people see the value.
• 7. Use QC data in supplier and design reviews. Feed nonconforming material data, incoming failure rates and test trends into supplier scorecards and product design discussions, not just into release decisions.
• 8. Train on writing and using specs. Make sure production and QC staff actually understand where specs come from, what they mean and how they relate to safety, performance and regulatory commitments.
• 9. Review QC as part of management review. Use V5 reports on QC failures, OOS, lab cycle times and release performance as routine inputs into management review and investment planning, not just as background noise.

The goal is not to “test more”. It is to test intelligently, link QC into everyday operations, and make sure that when QC finds something, the system actually learns and reacts.

FAQ

Q1. Is quality control the same as inspection?
Inspection is one tool within quality control – usually focused on visual, dimensional or functional checks. Quality control also includes lab testing, in-process measurements, sampling strategies, SPC, OOS handling and release decisions. If your QC is “we inspected the parts”, you are probably missing several critical elements.

Q2. Do we need in-process controls if final product testing is strong?
Yes. End-product testing alone is expensive and often too late to prevent loss. In-process controls allow you to detect and correct drift early, reducing scrap and rework and improving consistency. In some regulated areas, relying solely on end testing would not satisfy expectations for process understanding and control.

Q3. How many samples are ‘enough’ for QC?
There is no one-size-fits-all answer. “Enough” depends on criticality, process capability, risk, regulatory expectations and customer requirements. That’s why formal sampling plans exist. The key is to justify your sampling statistically and by risk, document it, and follow it consistently.

Q4. Is it bad if QC finds a lot of failures?
Not necessarily. A spike in QC failures may mean the process is unstable, but it also means your control system is catching issues before release. The worrying scenario is when QC almost never fails anything, yet complaints, returns or internal rework tell a different story. Trends and root causes matter more than absolute counts.

Q5. How does integrating QC into V5 change day-to-day work?
Operators see QC prompts and record results directly in V5 as part of their normal workflow. Labs and inspectors feed results into the same model that holds batches and inventory. QA reviews complete data in one place when deciding on release. Planners and managers can see QC status and trends without chasing spreadsheets. In short, QC stops being “someone else’s system” and becomes part of how the plant runs.

Related Reading
• QC Building Blocks: Quality Control – Testing & Release Evidence | In-Process Control Checks (IPC) | GMP Sampling Plans | Statistical Process Control (SPC) | Out of Specification (OOS)
• Records & Traceability: Batch Manufacturing Record (BMR) | Device History Record (DHR) | Traceability & Lot Genealogy
• Systems & V5 Platform: Quality Management System (QMS) | V5 Solution Overview | V5 MES – Manufacturing Execution System | V5 QMS – Quality Management System | V5 WMS – Warehouse Management System | V5 Connect API