Validation: What is validation?

The seemingly simple question "What is Validation?" has different answers depending on your viewpoint and professional background. For example, I have spoken with scientists who use statistical analysis software. Their view of validation is straightforward software testing; put numbers in and check the numbers that come out.

But then what about related terms such as Qualification, Verification and Testing? Why use a term such as validation when you can just say Testing?

Within the regulated Life Sciences sector, validation is more that just software testing. And we can show how Validation defines an overall framework incorporating Qualification, Verification and Testing.

Define Validation

First, let's define Validation...or rather let the FDA define it for us:

Establishing documented evidence which provides a high degree of assurance that a specific process will consistently produce a product meeting its predetermined specifications and quality attributes.

There are some key terms here that we should take note of:

documented evidence: We need to write stuff down that shows evidence of validation; it is not enough to go test something and then say it's validated.

specific process: This is what makes validation different from verification or testing. Validation is about the process, not just the tools (software) used to execute the process.

predetermined specifications and quality attributes: we need to define what the process should do and how before we execute the process.

Qualification, Verification and Testing

So Validation addresses the entire system, including software, underling hardware (infrastructure), business process, operating procedures, training, life cycle through to retirement.

The validation of a system will encompass one or more Qualification phases. These may focus on a life cycle phase (e.g. design phase, installation) or may focus on a specific component (e.g. infrastructure, support services).

A Qualification phase will comprise some activities such as planning, specification, design, analysis. One of these activities will be a Verification activity. There are different types of verification activity, depending on the scope of the qualification phase. For example a design qualification phase will generally have code review and design review as verification activities.

Obviously, one form of verification is Testing. For example, an Operational Qualification phase would include System Testing, Integration Testing, User Acceptance Testing, etc...as verification activities.

Here is a diagram that should put everything in context: