Glossary · Automation software engineering and architecture
Integration test
Also known as: Integration testing
German: Integrationstest
In software and systems engineering, an integration test is a test that checks the interaction between integrated components or systems, including their interfaces, data exchange and timing, to find defects that do not appear when the components are tested in isolation.
- Software engineering
In one sentence
An integration test checks the interaction between integrated components or systems, including interfaces, data exchange and timing.
Example
The integration test connects the line PLC, the MES interface and a simulated label printer and checks that each completed order produces exactly one correct label.
How it applies
- Engineering: Integration tests focus on interfaces: data formats, units, sequences, error cases, timeouts and behavior under load. In automation projects, they often involve PLCs, drives, HMIs, robots and higher-level systems from different suppliers.
- Commissioning: Many integration problems appear only on site, so testing interfaces early with simulations, Hardware-in-the-loop test rigs or virtual commissioning pays off.
- Documentation: Derive integration test cases from the Interface specification or Interface control document (ICD), and record results by interface and version. Deviations found during integration often reveal gaps in interface documentation that should be fixed at the source.
Integration test vs. component and acceptance test
A Component test checks one component in isolation; an integration test checks components together; an Acceptance test checks whether the whole system meets the customer's criteria. The levels build on each other, and each finds different kinds of defects.