Quality Control (QC) – Testing & Release Evidence

This topic is part of the SG Systems Global regulatory & operations glossary.

Updated October 2025 • Analytical & Release Controls • QC, QA, Manufacturing, Supply Chain

Quality Control (QC) is the disciplined practice of verifying that materials, intermediates, and finished goods meet approved specifications through scientifically sound sampling, validated/verified methods, qualified instruments, and trustworthy records. QC doesn’t just “run tests”—it generates release‑grade evidence that underpins product disposition, traceability, and trend analysis. Effective QC is inseparable from data integrity (Data Integrity; 21 CFR Part 11; Annex 11), validated systems (CSV, GAMP 5), qualified equipment (IQ/OQ/PQ), and lifecycle process control (Process Validation, PPQ, CPV). When QC is designed well, results are reliable, exceptions are rare, and release is fast and defensible.

“QC turns measurements into decisions—only when evidence is complete, attributable, and within spec should product move.”

1) QC’s Role and Boundaries

QC verifies conformance through tests that are fit‑for‑purpose and conducted under control. It is distinct from QA (system governance and release authority) and from production (execution of the process). QC owns analytical methods and laboratory workflows, monitors in‑process controls (IPC) with operations, and issues certificates like the CoA. QC also supports packaging verification (e.g., barcode checks) and incoming material control. Oversight frameworks include GMP, ICH Q10, and—where applicable—ISO 13485 for device labs.

2) Specifications, Methods, and Sampling Plans

QC translates quality requirements into measurable specifications and test instructions. Specifications should reflect patient/customer risk and process capability (Cp/Cpk) and be documented in controlled procedures (SOP, Document Control). Sampling must be statistically sound and risk‑based—see Statistical & GMP Sampling Plans and AQL—and appropriate to material heterogeneity and stage (incoming, in‑process, finished goods). QC defines when resampling is justified and forbids “testing into compliance.”

3) Sample Lifecycle and Chain of Custody

Accuracy begins with the right sample. QC controls sample ID, container, preservation, storage conditions, and custody from pull to disposal within LIMS. Sampling steps should be guided (barcoded materials, locations, lots) with Barcode Validation. For identity or contamination‑sensitive work, use segregated tools and areas, documented cleaning status, and—if relevant—monitor with Environmental Monitoring (EM). Where time affects results, follow approved hold‑time rules and, if applicable, evidence via Hold Time Studies (HTS).

4) Method Readiness: Validation, Verification & MSA

Methods must be proven fit for their intended use before routine QC. That includes selectivity/specificity (e.g., identity testing), accuracy, precision, range, and robustness. Transfer/verification is documented under controlled change. QC also evaluates measurement systems with MSA, including gauge R&R, linearity, bias, and stability; the goal is to ensure the test can reliably distinguish in‑spec from out‑of‑spec product and support SPC decisions without signal loss or false alarms.

5) Instrument & Asset Control

Results are only as good as the equipment. QC requires installation and operational checks (IQ/OQ), performance qualification where relevant, and strict adherence to calibration status. System suitability must be routine (e.g., HPLC resolution/plate count)—see HPLC. Moisture methods may use Karl Fischer. New complex instruments should pass FAT and then site IQ/OQ before release to production testing. All use is documented under Part 11 controls with audit trails and electronic signatures binding results to users and time.

6) Electronic Records: LIMS/ELN, Part 11 & Data Retention

QC’s core systems must be validated (CSV) and compliant with Part 11/Annex 11. LIMS and ELN should enforce unique credentials, role‑based permissions, time synchronization, and immutable audit trails. Raw data (chromatograms, balance files, images) must be complete and linked to processed results and approvals. Retain records per defined schedules (Data Retention & Archival), ensuring future reviewers can reconstruct the full story—who did what, when, why, and with which instrument and standard lots.

7) Incoming Materials: Gatekeeping for Quality

At Goods Receipt, materials enter Quarantine pending QC review and Incoming Inspection. QC confirms labeling, supplier lots, and documentation (e.g., CoA), performs identification (ID testing), and executes sampling plans sized to risk. Failures become NCMRs for MRB; chronic supplier defects escalate via SCAR. Status control in WMS prevents released/blocked mixing and supports FEFO/FIFO (FEFO/FIFO).

8) In‑Process Controls (IPC), PAT & Trending

Modern QC partners with operations to monitor the process, not just the end product. IPC checks verify critical parameters and attributes at the right frequency and with the right precision (IPC). Process Analytical Technology (PAT) and at‑line sensors reduce lag between cause and detection; trends are managed with SPC control limits to prevent drift becoming scrap. QC distinguishes OOT (warning) from OOS (failure), quantifies capability (Cp/Cpk), and feeds insights to CPV and APR/PQR. A tighter process creates fewer borderline results and a faster, cleaner release file.

9) Packaging, Labeling & Traceability Checks

QC checks don’t stop at chemistry. Mislabeling is a top recall driver. QC partners with packaging to verify artwork and variable data under Labeling Control, enforce at‑line label verification, and confirm identifiers like GS1 GTIN, SSCC, and unit serialization are correct. Event data exchange via EPCIS strengthens genealogy, enabling rapid, surgical recalls instead of blunt action. QC also confirms storage and shipping conditions meet GDP, including status checks during Pack & Ship and scan‑verified Dock Loading handover.

10) Environmental, Micro & Cleanliness Controls

For aseptic, sterile, or sensitive products, environmental data can be as critical as assay results. QC reviews EM trends, alarm responses, and excursion impact assessments. Cleaning verification/validation (Cleaning Validation) must be current to avoid cross‑contamination; QC may verify residues between lots and confirm equipment status at start‑up. Where human interfaces are involved, QC helps ensure HMIs and poka‑yoke controls reduce error opportunities during sampling and labeling.

11) Release Evidence: From Raw Data to CoA

QC’s output is a coherent evidence package: raw data linked to processed results, calculations, approvals, and conclusions, culminating in a CoA for customer/regulatory use. Evidence is referenced inside the eBMR to support QA’s Lot Release/Finished Goods Release. The package must show the method version, instrument IDs with calibration status, system suitability, sample provenance, and any deviations with assessed impact and CAPA. Clarity and completeness shorten QA review and accelerate shipment without sacrificing rigor.

12) Handling OOS/OOT: Investigation with Integrity

When results breach specs (OOS) or drift atypically (OOT), QC initiates a structured investigation. Phase‑1 confirms data integrity: sample identity, instrument status, calculations, and audit trails. Only when a plausible, documented assignable cause exists should retesting/resampling occur per SOP and sampling rules. If integrity stands and no bias is proven, the OOS informs process‑level investigation and disposition via MRB (MRB), with actions tracked under CAPA. OOT analysis should feed SPC, capability, and CPV to prevent future failures.

13) Deviations, Nonconformances & Supplier Feedback

QC documents lab errors, test anomalies, and material failures through Deviations/NCs and NCMRs. Evidence supports MRB decisions (rework, scrap, use‑as‑is with justification). Recurring causes become CAPA with effectiveness checks. For supplier issues, QC collaborates with procurement and QA to raise a SCAR, aligning expectations through controlled change and verification before returning to routine acceptance levels.

14) Change Control and Validation Bridge

Methods, limits, and systems evolve. QC participates in Management of Change/Change Control, defining impact and testing for instruments, software, labels, and specifications. Significant changes can trigger re‑qualification (IQ/OQ/PQ) or process re‑validation (PV/PPQ). QC ensures method readiness and data integrity are proven before live use; evidence is summarized for QA and auditors.

15) QC Metrics & Continuous Improvement

• Turnaround time (TAT): Sample receipt to result approval; segment by test type and bottleneck asset.
• Right‑first‑time (RFT): Results approved without correction or rework; correlates with training and method robustness.
• OOS/OOT rates & cycle time: Proportion and time to closure; percent with confirmed assignable cause.
• Capability & control: Cp/Cpk and SPC health on CTQs; links to OEE stability for process context.
• Asset readiness: On‑time calibrations, system suitability failures per 100 runs, unplanned downtime.
• Release impact: QA queries per batch for QC data; elapsed time from last result to Lot Release.
• Supplier quality: Incoming failure rate, SCAR count/closure time.

QC should link its metrics to business outcomes—yield, OTIF, and lead time—so leaders see quality as a performance enabler, not a cost center.

16) How This Fits with V5 by SG Systems Global

V5 Solution Overview. The V5 platform is engineered for laboratory‑grade control across manufacturing, quality, and logistics. Configuration is versioned; evidence is attributable; interlocks (identity, status, signatures) are enforced and reportable—ideal for QC rigor and rapid, defensible release.

V5 MES. In the V5 MES, QC integrates IPC checks, device data (balances, machine vision), and SPC limits directly into the step logic of effective‑dated MBR/MMR. Results feed the eBMR with audit trails and e‑signatures so QA can review by exception.

V5 QMS. Within the V5 QMS, QC governs method/SOP control (Document Control), manages investigations (NC, OOS), drives CAPA and MOC, and compiles trend packs for APR/PQR. Part 11 controls and audit trails are built‑in.

V5 WMS. The V5 WMS secures QC status—Quarantine to Released—prevents wrong‑material use through Directed Picking, enforces FEFO/FIFO, and validates labels/serialization (GTIN, SSCC, unit serialization) at Pack & Ship and Dock Loading. The same controls QC checks are the ones the platform enforces, closing the loop from lab to logistics.

Bottom line: V5 operationalizes QC. The controls you test—identity, limits, status, signatures—are the controls the platform applies at weigh, make, test, label, store, and ship, yielding faster release with stronger compliance.

17) FAQ

Q1. How is QC different from QA?
QC performs testing, manages methods and instruments, and compiles release evidence. QA governs the system, reviews evidence independently, and makes the release decision.

Q2. What belongs in a release evidence package?
The controlled method and version, instrument IDs and calibration status, system suitability, sample provenance and custody, raw and processed data, approvals (e‑signatures), and any deviations/CAPAs with impact assessments—referenced inside the eBMR plus the final CoA.

Q3. When is retesting or resampling allowed for OOS?
Only when Phase‑1 shows a plausible, documented assignable cause that could have biased the initial result. Counts and acceptance criteria must be predefined in SOPs; totality of data drives the conclusion, not the most favorable run.

Q4. How does QC ensure data integrity?
By using validated systems with unique users, meaningful e‑signatures, time‑synced servers, and immutable audit trails; by retaining complete raw data; and by enforcing Document Control over methods and templates.

Q5. Which QC metrics matter most?
TAT and RFT for lab efficiency; OOS/OOT rate and closure time for investigation health; capability indices (Cp/Cpk); and release impact metrics (QA queries per batch, time from last result to release). Link to OTIF and complaints for business relevance.

Q6. How does QC interact with packaging and serialization?
QC verifies label artwork under Labeling Control, checks variable data with Label Verification, and confirms GTIN, SSCC, and unit serialization, with event data integrated via EPCIS.

Q7. What triggers QC method or system re‑qualification?
Instrument/software upgrades, method or specification changes, supplier changes affecting critical attributes, or negative CPV/APR trends. Route through MOC/Change Control and re‑OQ or re‑validate as justified.

Related Reading
• Governance & Records: GMP | ICH Q10 | ISO 13485 | Document Control | SOP | Data Integrity | 21 CFR Part 11 | Annex 11
• Lab & Methods: LIMS | ELN | MSA | HPLC | Karl Fischer | IQ/OQ/PQ
• Process & Release: Process Validation | PPQ | CPV | IPC | SPC Control Limits | Process Capability (Cp/Cpk) | OOS | OOT | eBMR | Lot Release | Finished Goods Release
• Materials, Labels & Distribution: Goods Receipt | Incoming Inspection | NCMR | MRB | Labeling Control | Label Verification | GS1 GTIN | SSCC | Serialization | EPCIS | WMS