Glossary · Systems engineering and MBSE
Model element
In model-based systems engineering, a model element is a uniquely identifiable item in a model, such as a function, component, requirement, risk, interface or test. Its identity stays stable when its name or content changes.
- Systems engineering
- Data and interfaces
In one sentence
A model element is a uniquely identified item in an engineering model, the unit to which trace links, versions and approvals attach.
Example
In the system model of a packaging line, the safety function “stop on guard open” is a model element with a stable ID, linked to its requirement, its hazard and its verification test.
How it applies
- Identity: Give each element a stable, unique ID. Trace links and evidence refer to the ID, not to the name.
- Integrated systems: When models are exchanged between tools or suppliers, IDs must survive the exchange. Globally unique identifiers such as an IRI help.
- Evidence: Versions, reviews and approvals attach to model elements. This makes it possible to see which parts of a model are validated and which are not.
- Technical documentation: Documentation topics can reference model elements, so that a change to an element flags the topics that describe it.
Model element vs. system element
A model element is an item in a model. A system element is an identifiable part of the system that the model represents. One system element is usually represented by one or more model elements.