GMP Audit Preparation Guide
How to prepare your facility for FDA and third-party GMP inspections — in 90 days
"The most common thing I hear from quality managers before an audit is: 'We think we're compliant, but we're not sure.'"
That uncertainty is expensive. An investigator who catches you unprepared will find violations that a prepared facility could have avoided. Preparation means building the documented, practiced quality system the regulations require — and making sure your team can demonstrate it to anyone who walks through the door.
Part 1: Understanding What Auditors Look For
FDA Inspections
FDA operates under a risk-based framework — looking for systematic failures, not every minor deviation.
- Identity testing of incoming ingredients
- Finished product specifications and testing
- CAPA system effectiveness
- Record integrity (contemporaneous, accurate, complete)
- Personnel training evidence
- Building and equipment maintenance
- Typically unannounced for domestic manufacturers
- Duration: 1–5 days for small facilities
- Observations recorded on FDA Form 483
Third-Party Audits (NSF 455-2, USP, UL GMP)
Scheduled in advance with published criteria — you can prepare precisely.
- Audit criteria are published — prepare precisely
- More process-focused than risk-focused
- Non-conformances classified as Major or Minor
- Major non-conformance must be corrected before certification
- Walmart, Costco, Amazon increasingly require NSF or USP
- Signals compliance maturity to customers and partners
Assess and Organize
Pull every quality document you have and assess its status:
| Document Category | Current? | Approved? | Accessible? |
|---|---|---|---|
| Quality Policy | |||
| Master Manufacturing Records | |||
| Batch Production Records (past 2 years) | |||
| Component Specifications | |||
| Finished Product Specifications | |||
| SOPs (Receiving, Production, QC, etc.) | |||
| Training Records | |||
| Equipment Calibration Records | |||
| CAPA Records | |||
| Supplier Qualification Files |
Conduct a formal self-assessment against the GMP regulation that applies to you — 21 CFR Part 111 (dietary supplements), Parts 210/211 (drugs), Part 117 (food), or ISO 22716 (cosmetics). Create a gap log:
| Gap | Regulation | Risk | Owner | Target Date |
|---|---|---|---|---|
| e.g. No identity testing for Ingredient X | §111.75 | High | ||
- What do you do when a batch fails a specification?
- How do you verify incoming ingredients meet your standards?
- Walk me through an OOS investigation
- What happens when a customer files a complaint?
- What do you do if you notice a problem during manufacturing?
- How do you know which procedure to follow?
- What do you do if you make an error in the batch record?
- How do you know your quality system is working?
- When did you last conduct a management review?
- What has your CAPA system identified as a systemic issue?
- SOPs are posted or accessible at points of use
- Cleaning equipment is stored properly and labeled
- Equipment maintenance logs are current and near the equipment
- Raw materials are properly labeled, quarantined, and segregated
- Reject/quarantine areas are physically separated and clearly labeled
- No visible contamination risk (exposed product near open drains, overhead pipes)
- Temperature monitoring devices are calibrated and logs are current
- Facility is in good repair (no peeling paint, damaged flooring, holes in walls)
Close Gaps and Train
- Establish a written identity testing procedure
- Validate or verify test methods
- Test all lots currently in inventory lacking documentation
- Contract with an accredited lab if needed
- Write specifications for every component and finished product
- Include: identity, purity, strength, composition, contaminant limits
- Get specifications approved and dated by QC
- Implement a CAPA system now — even a spreadsheet works if used consistently
- Write the CAPA SOP
- Open CAPAs for any known quality issues
Ensure every quality and production employee has documented training on your SOPs.
Training records must include: name, date, SOP or topic, trainer signature, and employee signature.
During an inspection, if you can't find a record, an investigator may conclude it doesn't exist. Records should be retrievable in minutes, not hours.
- Batch Production Records: by lot number and product
- Lab records: by test and date
- CAPA files: organized and numbered
- Complaint files: organized and indexed
Practice and Finalize
Have someone unfamiliar with your day-to-day operations conduct a formal mock inspection: walk the facility as an investigator would, request records the way FDA would, interview key personnel. Score the mock inspection and close any remaining findings before the real inspection.
With the investigator at all times. Answers regulatory questions.
Retrieves requested records quickly. Pre-organizes binders.
Production/lab manager available for technical questions.
- All high-priority gaps from Month 1 are closed and documented
- Training records are current for all employees
- Equipment calibration and maintenance logs are current
- Batch records for the past 2 years are organized and accessible
- CAPA files are organized and current
- Escort team and records team are briefed and ready
- Management is prepared and briefed on known risks
Inspection Day: Quick Reference
| Document | Location | Person Responsible |
|---|---|---|
| Batch Production Records (past 2 years) | Records Room / Binder | QA Admin |
| Master Manufacturing Records | QA Office | QA Manager |
| Component Specifications | QA Office / LIMS | QA Manager |
| Lab Test Records | Lab / LIMS | Lab Manager |
| Equipment Calibration Log | Maintenance Office | Maintenance Lead |
| CAPA Files | QA Office | QA Manager |
| Training Records | HR / QA Office | HR / QA |
| Supplier Qualification Files | QA Office | Procurement / QA |
| Distribution Records | Shipping / ERP | Operations |
NSF/ANSI 455-2 Specific Preparation
Documents Required for NSF Document Review
- Quality manual or quality policy
- All SOPs referenced in your quality system
- Master Manufacturing Records for each product to be certified
- Sample Batch Production Records
- Lab records and method validations
- CAPA records and corrective action trends
- Supplier qualification files
- Training program and records
Questions NSF Auditors Commonly Ask
- “Show me how you would handle this hypothetical situation” (tests practical application)
- “What was the root cause of the last CAPA you opened?”
- “What trends has your CAPA system identified in the past year?”
- “Walk me through your supplier qualification process for a new ingredient supplier”
- “How do you know your test methods are reliable?”
Need Support Preparing for an Audit?
We offer gap assessments, mock inspections, SOP development, CAPA system design, and escort team training. Free 30-minute assessment call — no obligation.
Schedule a Free Assessment CallJared Clark, CPGP, CQA, RAC | The GMP Consultant — a Certify Consulting Group service | thegmpconsultant.com | 858-240-4353
This guide is for educational purposes only and does not constitute regulatory or legal advice. FDA inspection procedures and third-party audit criteria are subject to change. Consult current FDA guidance and NSF, USP, or UL audit criteria for the most current requirements. © 2026 Certify Consulting Group.