hisl_0070: Placement of requirement links in a model
|ID: Title||hisl_0070: Placement of requirement links in a model|
Establish bidirectional traceability between model requirements and the model elements that are used to implement the requirement. A single element or combination of elements can link to requirements.
When linking requirements, follow these guidelines.
|A||Apply requirement links to the lowest level component of model elements. Model elements that do not impact the model's behavior or the generated code are exempt from requirement linking. See Notes for additional information.|
|B||At the project level, define the maximum number of unique requirement links associated with each component. A minimum of one requirement link is required.|
|C||At the project level, define the maximum number of child model elements for each linked component.|
Use Requirements Toolbox™ to trace between the model and the requirements from which the model was developed. Apply user tags (Requirements Toolbox) to define model elements as derived and/or safety requirements.
To reduce the number of requirements that are linked to a model, apply requirements at the component-level. A component contains a group of model elements, for example:
Components that contain only these model elements are exempt from requirement linking:
When a linked component contains a nonexempt child model element, the child implements the associated requirement either in part or whole.
|Rationale||A||Establishing requirement links at the component level captures the relationship of model elements. In addition, maintainability improves because the need to update requirement links for minor logic changes is reduced.|
|B, C||Support requirement change impact analysis.|
|Model Advisor Check||Check for model elements that do not link to requirements (Simulink Check)|
Requirements Traceability (Requirements Toolbox)
Recommended: Requirement links on parent component
Requirement link placed at the top level model with no subsystems.
Recommended: Requirement links placed on area annotation
Requirement link placed on an area annotation.