Create Exclusive Exhaustive Requirements

Since R2023b

You can use exclusive exhaustive requirements to create non-overlapping and complete sibling requirements. When you run the simulation, the Requirements Table block checks that exactly one exclusive exhaustive sibling requirement is active at each time step. The block returns an error if more than one or no exclusive exhaustive sibling requirement is active at any time step. You can create first-level hierarchy exclusive exhaustive requirements by specifying the child evaluation of the requirements table, or create exclusive exhaustive child requirements by specifying the child evaluation for a parent requirement. For more information on requirement hierarchy and child evaluation, see Establish Hierarchy in Requirements Table Blocks and Specify Child Evaluation in Requirements Table Blocks.

Specify Exclusive Exhaustive Evaluation for First-Level Hierarchy Requirements

To create exclusive exhaustive first-level requirements, ensure that a row is not selected, and, in the Rows section of the Table tab, set Evaluation to Exclusive Exhaustive. The exclusivity icon indicates that the first-level hierarchy requirements are exclusive exhaustive. Only the requirements in the first level of hierarchy become exclusive exhaustive. Lower-level requirements are not exclusive exhaustive and are evaluated independently.

For example, in this table, the block checks that only one of requirement 1, 2, or 3 is active at every time step.

Requirements table with three first-level requirements that display the exclusivity icon in the index column.

You can create exclusive exhaustive first-level requirements programmatically by setting the ChildEvaluation property of a RequirementsTable object.

Specify Exclusive Exhaustive Evaluation for Child Requirements

To make the children of a parent requirement exclusive exhaustive, select the row index of a parent requirement. Then, in the Table tab, in the Rows section, set Evaluation to Exclusive Exhaustive. The exclusivity icon indicates the requirement is exclusive exhaustive. When you specify an exclusive exhaustive child evaluation for a parent requirement, only the direct children of the parent requirement become exclusive exhaustive. Lower-level requirements are not exclusive exhaustive and are evaluated independently.

In this table, the child evaluation of requirement 1 is exclusive exhaustive and the child requirements 1.1, 1.2, and 1.3 display the exclusivity icon.

Requirements table with an expanded parent requirement with exclusive exhaustive child requirements and a second collapsed parent requirement. The child requirements display the exclusivity icon in the index column.

To remove the exclusive exhaustive child evaluation a parent requirement, click the parent requirement row index and set Evaluation to Independent.

You can create exclusive exhaustive child requirements programmatically by setting the ChildEvaluation property of a RequirementRow object.

Validate Exclusive Exhaustive Requirements

If you have Simulink^® Design Verifier™, you can validate your exclusive exhaustive requirements by analyzing the table for exclusivity issues before running the simulation. To analyze the block, in the Table tab, click Analyze Table. For more information on analysis and exclusivity issues, see Detect Exclusivity Issues in the Requirements Table Block.