IQ OQ PQ Process Validation: Full Theory & Praxis

The IQ OQ PQ process validation methodology, standing for Installation Qualification (IQ), Operational Qualification (OQ), and Performance Qualification (PQ) sequence constitutes the established framework for process validation, serving as the systematic generation of documented evidence that a manufacturing process is in a state of control. This methodology follows a deliberate and logical progression, beginning with the static, documented verification that equipment is installed correctly (IQ), moving to the dynamic confirmation that the equipment operates reliably across its specified ranges (OQ), and culminating in the demonstration that the integrated process consistently produces product meeting all quality attributes (PQ).

The entire sequence is designed to provide objective, traceable proof that the process is robust, reproducible, and fit for its intended purpose before commercial use.

This methodology is a non-negotiable regulatory prerequisite in industries governed by cGMP, such as pharmaceuticals, biologics, and medical device manufacturing, where process consistency is directly linked to patient safety. Its application is not for initial research but is the critical validation stage conducted after process development is finalized and before the process is approved for routine commercial production.

Key Takeaways

• Validation’s output is evidence, not product.
• “Worst-Case” OQ testing involves combined stressors.
• PQ validates the integrated process, not just the equipment.
• The “Three Batch” rule demonstrates reproducibility.
• PQ success is defined by consistency, not just passing spec.
• The protocol is a contract; deviations must be justified and well-documented.
• Leverage supplier documentation (FAT/SAT), but do not replace your own OQ
• Validation defines the start of the lifecycle, not the end of a project.
• Any “like-for-like” change requires justification.
• Personnel training is a prerequisite for OQ and PQ

Installation Qualification (IQ)

Installation Qualification (IQ) is the initial and foundational phase of the IQ OQ PQ process validation methodology. It is a formal, documented process that verifies and confirms that equipment, systems, and ancillary components have been delivered, installed, and configured in complete accordance with the manufacturer’s recommendations and the user’s design specifications.

The purpose and importance of IQ: the primary goal of IQ is to establish a baseline for the equipment’s validation. Before any operational testing can begin, it is crucial to ensure that the equipment is physically present, correctly assembled, and situated in an appropriate environment. This phase mitigates risks associated with improper installation, which could otherwise lead to equipment malfunction, product quality issues, and safety hazards.

Key Stages and Activities in Installation Qualification

The IQ process is systematic and involves several detailed stages, typically managed through a pre-approved protocol and checklist.

1. Pre-Installation and Planning

Before the equipment even arrives, or is even ordered, the IQ process begins with careful planning. This includes:

• Site readiness verification: ensuring the designated location is prepared for the new equipment. This involves checking for adequate floor space, structural support, and the availability of necessary utilities at the correct connection points.
• Environmental conditions: verifying that the installation environment meets the manufacturer’s specifications for temperature, humidity, and cleanliness.
• Gathering documentation: collecting all essential documents, such as the purchase order, manufacturer’s manuals, design specifications, engineering drawings, and calibration certificates for any integrated measurement instruments.

2. Equipment Receipt and Verification

Once the equipment is delivered, a thorough inspection is conducted:

• Component verification: the delivered items are meticulously checked against the packing list and purchase order to confirm that all components, including software, have been received and are the correct model and version ordered.
• Inspection for damage: a visual inspection is performed to ensure that no damage occurred during shipping and handling.

Note: in most industries practicing the IQ OQ PQ methodology, the equipment should come with its certificates of conformance (CE FDA markings …), eventually other certificates, and possibly some manufacturing own tests results. These documents should be considered in the same way and importance as the physical goods themselves. In fact a delivery should be refused if these documents are not included or received in advance (in quarantine zone at least).

3. Installation and Connection Verification

This is the core of the IQ process, where the physical installation is scrutinized:

• Correct assembly and placement: verifying that the equipment is assembled and positioned as per the manufacturer’s instructions and engineering drawings.
• Utility connections:this is a critical...

Related Readings

• Validation Master Plan (VMP): the high-level strategic document that defines the company’s overall validation philosophy, scope, responsibilities, and the specific systems and processes to be validated.
• User Requirement Specification (URS): the foundational document that details what the equipment or process is expected to do from an end-user and quality perspective, forming the basis for all subsequent testing.
• Factory Acceptance Testing (FAT) & Site Acceptance Testing (SAT): engineering-led precursor tests, often performed with the vendor, to verify equipment functionality before shipping (FAT) and after installation (SAT), which can be leveraged to streamline IQ/OQ.
• Computer System Validation (CSV): a specialized validation discipline that runs in parallel to IQ OQ PQ, focusing on the integrity, security, and reliability of the software and computerized systems controlling the equipment.
• 21 CFR Part 11 Compliance: the specific set of FDA regulations governing electronic records and electronic signatures, a critical component of CSV for ensuring data integrity, audit trails, and access control.
• Cleaning validation: a sometimes separated but related validation process performed on the same equipment to prove that a cleaning procedure can effectively and consistently remove product residues, cleaning agents, and microbial contamination (we strongly recommend to include it in the IQ OQ PQ protocol, as the cleaning status is an integral part of the product and process performances).
• Measurement System Analysis (MSA) / Gage R&R: the statistical methodology used to validate the *test methods* themselves, ensuring the measurement system used to judge product quality is accurate, precise, repeatable, and reproducible.
• Risk-based validation (using FMEA/HACCP): the methodology for identifying potential failure modes and risks to product quality, allowing validation efforts to be focused on the most Critical Process Parameters (CPPs).
• Critical Quality Attributes (CQAs) & Critical Process Parameters (CPPs): the specific, defined product characteristics (CQAs) and process variables (CPPs) that must be controlled to ensure the desired product quality, which form the acceptance criteria for PQ.
• Process Capability Analysis (Cpk/Ppk): the statistical analysis performed on PQ data to quantify how well a process is centered within its specification limits and how much variability it has, providing a numerical score of its “capability”.
• Continued Process Verification (CPV): the modern “Stage 3” of process validation, which involves the ongoing monitoring of process parameters and quality attributes during routine production to ensure the process remains in a constant state of control.
• Change control management: the formal quality system procedure for evaluating, documenting, and approving any proposed changes to a validated system or process to ensure it does not unintentionally exit its validated state.
• Deviation and CAPA management: the system for investigating, determining the root cause of, and implementing Corrective and Preventive Actions for any unexpected events or failures that occur during or after validation.
• Retrospective validation: an outdated validation approach, now rarely acceptable, based on analyzing historical production data from an existing, unvalidated process to attempt to prove it has been operating in a state of control.
• Validation Summary Report (VSR): the final, conclusive document that summarizes the entire validation effort (IQ OQ PQ), presents the key results, addresses any deviations, and formally declares the system or process as validated and fit for commercial use.