Modeling Guide
Knowledge Guides /How Should a SysML Profile Be Customized? Define Meaning before Extending Elements
Last updated: · New Horizon Digital Outsourcing Team
Start Profile customization with domain concepts that the existing modeling language cannot express clearly enough. Define the extended elements, attribute meanings, and usage constraints. A new icon or menu demonstrates usability; preserved meaning after saving, reopening, and dependency resolution still needs checking.
Decide Whether an Extension Is Needed
- Map domain terms to existing model elements, distinguishing different names, additional attributes, and usage rules. Preserve existing semantics where they already express the concept clearly rather than creating a type for every project-specific name.
- For each necessary extension, write its definition, applicable elements, and counterexamples, and assign ownership. Confirm shared understanding with a few general examples before extending engineering models; a project label is not an explanatory definition.
Define Attributes and Constraints
- Define each property's type, unit, allowed values, required status, and default meaning. Use positive and negative examples for easily confused concepts, keeping missing data, real zero values, and non-applicable items distinct.
- Separate automatically checkable rules from those requiring judgment and specify how failures should identify the affected element. Tool-specific configuration objects, drawing menus, and shortcuts should not be presented as universal language rules.
Check Semantics and Presentation Separately
- Use one valid example and one deliberately invalid example to check whether the extension applies to intended elements, properties can be read, and violations are detected. Consistent graphics do not replace checks of object types and properties.
- Save, close, and reopen the examples, then recheck properties, references, and required validation rules. Record dependencies and versions when sharing with another environment; visible elements do not prove that extension definitions and constraints still resolve.
Maintain the Extension as a Deliverable
- Deliver concept definitions, extension definitions, an attribute dictionary, examples, and known limits, identifying tool-specific configuration. Before changing property types or allowed values, inspect existing models and resolve invalid values without overwriting their meaning with new defaults.
- This method applies to a defined language and tool combination that uses Profiles. It does not establish direct migration of SysML v1 extensions to SysML v2. A migration needs separate checks of target-language expression and tool support, with unverified areas recorded.