Glossary · Requirements and interfaces
Interface control document (ICD)
Also known as: ICD
German: Schnittstellenkontrolldokument (ICD)
In systems engineering, an interface control document (ICD) is a controlled document defining the technical and organizational requirements of an interface. It is agreed by the owners of both sides and changed only under change control.
- Data and interfaces
- Technical documentation
- Systems engineering
In one sentence
An interface control document (ICD) fixes the technical and organizational requirements of an interface and is agreed by both sides.
Example
The ICD between a machine builder and a line integrator defines the safety signals exchanged, their timing, the emergency stop linkage and who performs the joint validation.
How it applies
- Integrated systems: Use the ICD as the contract between the parties at an interface. Both owners sign it, and changes require both.
- Organizational content: Besides signals and data, the ICD should state responsibilities: who operates, maintains, changes and verifies each side. See responsibility assignment.
- Technical documentation: The ICD is a controlled document with version, status and approval. Instructions and service documents refer to it rather than copying its content.
- Evidence: Integration tests reference the ICD version they verify.
ICD vs. interface specification
An interface specification defines the behavior at an interface in technical detail. The ICD is the controlled, agreed document that fixes the interface requirements, including organizational ones, and may contain or reference the specification.