Validation Testing of

Computerized Systems

In the healthcare sector, critical systems—that is, those directly impacting patient safety, product quality, or data integrity—must comply with regulatory requirements. While validating computerized systems isn’t limited to testing, tests remain central in the process, being integrated at different steps of the system lifecycle.

Within the testing landscape, validation tests are not the only ones. Even non-critical systems—by GxP regulation—must undergo tests prior to use: these are verification tests. Verification tests are engineering tests, managed by the Project team, and must be supplemented by validation tests when a system is considered critical for use in regulated processes.

Let’s take a look at all the tests performed on a validated critical system before it goes live. We’ll follow the lifecycle, starting with verification tests. These often begin in initial development or configuration phases with supplier-side tests, followed by acceptance tests on the client side.

They are complemented by validation-specific tests in regulated industries as part of a risk management approach (IQ / OQ / DMT / PQ).

Thus, tests are not limited to simple technical verification—their purpose is compliance: they constitute documented evidence that the system is reliable, compliant, and fit for use in a regulated environment.

In conclusion, any critical system operated in a regulated environment is subject to numerous tests throughout its lifecycle. Validation teams can optimize effort by leveraging verification tests, provided regulatory requirements are met. This decision must be justified and explained in the validation strategy.

Unit tests check the functioning of each code unit, generally at the functional component level (like menus). These tests are usually automated and detect flaws early to correct errors in the first phases of development. They are the first verification step, carried out by the developer and integrator in a defined development environment.

Integration tests verify that the assembled elements of the software work correctly together. They help detect interaction issues between modules or services, verifying interfaces and data flows. These follow unit tests, typically performed by the integrator or development team in a test environment simulating client use.

System software tests check the operation of the entire system to ensure it meets specified requirements. The goal is to validate the interaction of all integrated components and verify that the system works as intended in a simulated or real environment. Usually, these tests are performed after full integration, often by the validation team or client, in a client test environment replicating operational conditions (called the production environment).

User Acceptance Tests (UAT) are performed to confirm the system meets end-user needs and requirements. These often involve scenarios based on real use cases to verify the system is ready for production and meets user expectations. UATs are conducted at the end of development, before deployment to production, by end users or client representatives in a client environment faithful to production.

Installation Qualification (IQ) tests check that the system’s installation and configuration comply with supplier specifications and client requirements. This includes physical installation, software setup, client-specific settings, and related documentation. These tests ensure control over validation and production environments, performed by the validation team.

Operational Qualification (OQ) tests validate critical system functions to ensure they meet defined operational specifications. These tests include regulatory requirements for safety and data integrity, as well as verification of interfaces with other systems. They ensure reliable system operation under expected conditions and are conducted after IQ in the validation environment by the validation team.

Data Migration Qualification (DMQ) tests specifically check the transfer of data from a source to a target system. They verify accuracy, consistency, and integrity after migration, forming part of the migration management process for system upgrades or replacements. Conducted in validation or pre-production environments by the validation team with close collaboration from integration and IT.

Performance Qualification (PQ) tests check the efficiency and reproducibility of processes implemented by the computerized system regarding end-user requirements. These tests evaluate the user’s ability to control the system and its data in the final operating environment (production) via defined organizational measures. They are performed after IQ in the production environment by the validation team.