Inside the GMP Inspection Process, Explained
We map the GMP inspection process end to end, showing what regulators check, who is responsible, and where compliance often breaks down.
Every pharmaceutical manufacturer will eventually sit across the table from a GMP inspector, yet the GMP inspection process itself is rarely discussed as a discipline in its own right.
We map what actually happens before, during, and after an inspection, and who is responsible for what, to offer a rare, structured view of an event that most only experience under pressure.
What Does the GMP Inspection Process Cover?
A Good Manufacturing Practice (GMP) inspection exists to confirm that a facility can consistently produce medicines that meet the quality, safety, and efficacy standards patients rely on.
Regulators including the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA) each run their own inspection programmes, but they converge on the same underlying structure.
Inspectors organise their review around what is described as the five P's: Premises, procedures, processes, people, and products.
Premises covers the physical facility, procedures are the documented ways of working, processes are the repeatable activities that keep production consistent, people are the personnel who execute and oversee everything, and products are assessed against the company's own quality evidence.
Every other inspection activity sits underneath one of these five headings.
The stakes are high. One analysis of 99 GMP inspection reports across 19 countries over 10 years identified 1,458 deficiencies, of which 37% were classified as major and nine per cent as critical.
Inspection volumes are not static either. One study found the number of inspections fell by 40%, from 1,748 in 2018 to 1,106 in 2020, during the disruption of the pandemic.
A failed or delayed inspection is not simply a paperwork problem. Poor inspection outcomes and quality breaches can force a manufacturer to halt production while it investigates the root cause, and that pause can ripple outward into drug shortages and treatment delays for patients waiting on that medicine.
Quality breaches, in turn, are often not detected until after a product has already reached the market, which is precisely why inspection management deserves attention as its own discipline rather than a once-a-year formality.
How Should Pharma Companies Audit AI Vendors?
“This is one of the riskiest industries there is because you're dealing with human lives, you're dealing with experimental protocols, and you're dealing with regulatory bodies where you might not get another shot at that clinical trial."
Who Is Involved, and What Must Each Side Do in the GMP Inspection Process?
A GMP inspection has two sides, each with distinct obligations.
On the regulatory side, inspectors are expected to hold relevant qualifications, receive at least 10 days of training a year, and operate with no political involvement and no discrimination, in line with the values set out by the Pharmaceutical Inspection Co-operation Scheme (PICS), the international body that harmonises inspection standards across more than 50 regulatory authorities.
Inspectors with any financial or personal ties to the facility under review are expected to step aside.
On the manufacturer’s side, responsibility sits with the company’s quality unit, supported by subject matter experts who must be available throughout the visit. A designated ‘war room’, stocked with organisational charts, quality manuals, SOPs, and training records, is a recurring feature of well-prepared facilities.
During interviews, manufacturer staff are expected to answer clearly and factually, using what is sometimes called the CLEAR method: Clarify the question, listen completely, express concisely, avoid speculation, and remain focused.
Responsibilities on both sides typically include:
- Regulators select inspectors with the right technical qualifications and no conflicts of interest
- Regulators give advance notice for most inspections, typically four to six weeks, though unannounced visits do happen
- Manufacturers keep a designated response team and quality-unit representative available throughout
- Manufacturers maintain documentation that is current, complete, and immediately retrievable
- Both sides commit to open, factual communication rather than adversarial exchanges
The Three Phases of a GMP Inspection
Beyond the roles involved, the inspection itself follows a broadly consistent three-phase structure: Preparation, execution, and follow-up.
Pre-inspection preparation
Most manufacturers receive four to six weeks’ notice before an inspection, although unannounced visits do occur.
Preparation typically covers personnel training, documentation review, equipment checks, and an internal risk assessment, often supported by a self-inspection or mock audit beforehand.
Manufacturers are usually asked to submit a site master file and previous inspection reports in advance, which regulators use to build an inspection plan one to two weeks ahead of the visit.
Execution, on site
Once on-site, EMA inspections typically run for three to five days, while FDA inspections can extend to two weeks or longer.
The visit generally follows a set pattern: An opening meeting, document and record review, a facility walkthrough, structured interviews with key personnel, and a closing meeting where inspectors share their initial observations before a written report follows.
Inspectors examine everything from sanitation and equipment maintenance to batch records, deviation handling, and computer system validation.
Post-inspection follow-up
A written report, or a warning letter where serious violations are found, typically follows within three weeks.
It sets out each deficiency, its classification, and a deadline for the manufacturer's response, usually with a root-cause analysis and a corrective and preventive action (CAPA) plan attached to every finding.
Once the response is accepted, the inspection closes with a close-out letter and, where applicable, a GMP certificate.
What the GMP Inspection Process Means in Pharma
An inspection’s most useful framing may be its borrowing of the idea of known knowns, known unknowns, and unknown unknowns.
Manufacturers usually prepare well for the compliance requirements they already know about. However, the more damaging findings tend to come from the unknown unknowns, or gaps such as a missing supplier audit programme, that nobody flagged until an inspector asked about it.
Regional context matters too.
Smaller manufacturers, which make up the overwhelming majority of firms in developing pharmaceutical markets, often have fewer resources to dedicate to inspection readiness than multinational operators working inside mature systems such as the European Union or the U.S.
Mutual recognition agreements between major regulators, allowing one authority to rely on another’s inspection findings, help narrow that gap, though differing interpretations of GMP standards still limit how far that reliance can go.
Looking ahead, digital tools are reshaping GMP inspection process management. Electronic quality systems can reduce transcription errors, blockchain-based records resist tampering, and AI tools are already being used by some regulators to prioritise which facilities and risk areas need inspection attention first.
One thing is especially worth flagging for anyone benchmarking their own compliance programme: Manufacturers are often reluctant to share product rejection data, even anonymously, which limits how much the wider industry can learn from any single facility’s near misses.
Wider reporting of post-inspection consequences and penalties, it’s argued, would strengthen accountability and help other manufacturers avoid the same deficiencies rather than rediscovering them independently.
AI in Pharma: Why the Future of Healthcare Starts With Patients, Not Tech
Kate O’Reilly, President & Chair of the Healthcare Businesswomen’s Association (HBA) Dublin-Ireland Chapter & Healthcare Transformation Partner at Roche, discusses AI in pharma, patient engagement, and the future of healthcare innovation.
Managing the GMP Inspection Process
The GMP inspection process is not a single event to be survived. It is the output of a three-phase management discipline, preparation, execution, and follow-up, that runs continuously in well-run facilities rather than starting when a regulator’s notice letter arrives.
Inspection readiness should be treated as a standing capability built on trained personnel, current documentation, and honest internal audits, rather than a project that begins only once a visit is confirmed.
At Pharmatica, we monitor the operational and regulatory disciplines that keep pharmaceutical manufacturing compliant at scale. Explore our Technical Operations Insights for more analysis on manufacturing quality systems, and see our related article on the FDA’s first AI-related CGMP warning letter for a closer look at what happens when inspection findings escalate.
Pharmatica: Insight. Connection. Impact.
Frequently Asked Questions
What is a GMP inspection?
A GMP inspection is a regulatory review of a pharmaceutical facility's premises, procedures, processes, people, and products, carried out to confirm that medicines are manufactured to consistent quality and safety standards.
Who conducts GMP inspections?
National and regional regulators, including the FDA, the EMA, and members of the Pharmaceutical Inspection Co-operation Scheme, conduct GMP inspections, typically using trained, independent inspectors with no financial or personal ties to the facility.
What are the three phases of a GMP inspection?
The three phases are pre-inspection preparation, on-site execution, and post-inspection follow-up, covering everything from staff training and documentation review through to corrective action plans and final close-out.
What happens if a GMP inspection finds deficiencies?
The manufacturer receives a written report or warning letter classifying each deficiency, and must submit a root-cause analysis and corrective and preventive action plan, usually within a set number of working days.
How long does a GMP inspection last?
Inspection length varies by regulator: EMA inspections typically run for three to five days, while FDA inspections can extend to two weeks or longer, depending on the facility’s size and complexity.
About the author
Did you enjoy the content?
Why not support Nicole Dale by giving this content a like
Comments (0)