What is the difference between qualification and validation?
Understand when equipment, systems, and processes must be qualified or validated.
Qualification and Validation
Qualification and validation are two concepts that are often confused—but they refer to different activities with different purposes.
Here you'll find a clear explanation of the difference and the most important requirements.
On this page, you'll find answers to:
- What is the difference between qualification and validation?
- What happens if you don't qualify or validate?
- What are IQ, OQ, PQ, and DQ?
- When should a process be validated?
- What mistakes and challenges are typically encountered in practice?
- What are the most important tips for qualification and validation?
- When should you qualify, validate, or reassess?
What is the difference between qualification and validation?
Qualification documents that equipment, facilities, and installations function as intended and meet predetermined requirements. Validation documents that a process consistently produces the desired and reproducible result. Qualification therefore applies primarily to equipment, while validation applies primarily to processes.
An easy rule of thumb: If you qualify the equipment, you validate the process.
In this video (in Danish), you'll get the explanation of the difference between qualification and validation in just under 3 minutes.
Qualification | Validation | |
Is about | Equipment, facilities, installations | Processes, Methods, Cleaning, IT |
Purpose | Document that the equipment is functioning as intended | Document that the process produces reproducible results |
Example | New autoclave is installed and tested (IQ, OQ, PQ) | The aseptic filling line is validated using media filling |
Source | EudraLex Vol. 4, Part I | Annex 15 (items 5, 9, 10) and Annex 11 |
Example:
You install a new temperature sensor in a cold room. Through the qualification process, you verify that the sensor and the monitoring system are functioning properly, both technically and during daily operation.
What happens if you don't qualify or validate?
Failure to perform qualification and validation is a critical GMP violation.
This can result in regulatory warnings (Warning Letters), bans on manufacturing or selling products, and batch recalls.
Internally, this means an increased risk that products will not meet the intended specifications.
It is not enough to have “used the equipment for years without any problems”—GMP requires documented evidence.
What are the four steps in equipment qualification?
Qualification is typically carried out in four stages: DQ (Design Qualification), IQ (Installation Qualification), OQ (Operational Qualification), and PQ (Performance Qualification).
| Step | Description | |
| 1 | DQ – Design Qualification | Have the requirements for equipment and functionality been thoroughly considered and documented? Does the design align with the URS? |
| 2 | IQ – Installation Qualification | Is the equipment installed correctly and does it meet both the supplier's and the company's specifications? |
| 3 | OQ – Operational Qualification | Does the equipment work as expected when tested under controlled conditions? |
| 4 | PQ – Performance Qualification | Does the equipment meet the requirements under normal operating conditions – in other words, during everyday production? |
Together, they demonstrate that the equipment is properly designed, correctly installed, functions as expected, and meets operational requirements.
Qualification isn't just about testing equipment; it's about showing that it actually serves the purpose it was bought for.
Source: EudraLex Vol. 4, Part I, chapter 1–9
When should a process be validated?
A process must be validated when it is used to manufacture GMP-regulated products and when reproducibility is critical to quality and patient safety.
Validation is all about documenting that a process consistently delivers the desired outcome.
Process validation requirements apply, among other things, to
- production processes
- cleaning procedures
- IT Systems
- analytical methods
Example:
You will ensure that an aseptic filling line consistently delivers sterile products.
You perform a process validation, using, for example, media fill to document it.
Source: EU GMP Guideline: IT Systems (computerised systems): Annex 15 (Principle) and Annex 11; Production: Annex 15, point 5; Analytical Methods: Annex 15, point 9; Cleaning: Annex 15, point 10.
What are the typical mistakes and challenges in practice?
- People often confuse PQ with process validation – but PQ is actually part of the qualification process.
- Changes to processes or equipment happen without change control – and without re-evaluating qualification/validation.
- Documentation is skipped because 'we've been using it for years without any problems, right?'
- Data lacks ALCOA+ quality – for instance, missing data loggers, uneditable files, or no review at all.
What are the most important tips for qualification and validation?
- Make active use of risk assessment—it is a requirement (Annex 15, sections “General” and 1.7) and helps you stay focused.
- Think about validation right from the start – set aside plenty of time early in the project for risk assessment, requirements (URS), and design. It's both expensive and time-consuming to fix things later if the requirements aren't clearly defined.
- Document everything – but only what's necessary – 'as built' vs. 'as documented' needs to match up.
- Get QA involved early – it ensures better planning and fewer roadblocks.
- Give your employees the training they need so they can fulfill their role in validation activities.
Checklist: Should You Qualify or Validate?
| Situation | Qualify | Validate |
| New equipment installed? | Yes | Not necessarily |
| Process changed? | Not necessarily | Yes |
| New software in production? | Yes | Yes |
| New cleaning agent? | No | Yes |
| Will existing equipment be modified? | Reassess* | Reassess* |
* "Reassess" means that you actively review and document whether existing qualifications or validation are still valid following the change—this is not the same as starting over, but the conclusion must always be documented.
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Need help putting these requirements into practice?
Here, you'll get knowledge you can use for upskilling, training, and your GMP work.
Use it in practice
- Team meeting task: Review a piece of equipment you use. Which steps in IQ, OQ, and PQ can you identify? Is it documented correctly?
- Glossary: Find terms like “performance qualification” and “change control” in our GMP glossary.
Download the GMP Dictionary (search for Pharmakon): App Store (iOS) or Google Play (Android)