hisf_0013: Usage of transition paths (crossing parallel state boundaries)

R2026b

Avoid creating transitions that cross from one parallel state to another

Usage: High-Integrity System Modeling

Guideline ID: hisf_0013

Rules

hisf_0013: Usage of transition paths (crossing parallel state boundaries)
A

To avoid creating diagrams that are hard to understand, avoid creating transitions that cross from one parallel state to another.

Rationale

Enhance model readability.

Verification

Check Stateflow charts for transition paths that cross parallel state boundaries (Simulink Check)

Example

In the following example, when Out_A is 4, both parent states (A_Parent and B_Parent) are reentered. Reentering the parent states resets the values of Out_A and Out_B to zero.

Stateflow chart with a transition crossing from parallel state A_Parent to B_Parent when Out_A equals 4

Scope with Out_A signal cycling 0 to 4 and Out_B signal cycling 0 to 5, both resetting periodically

Tips

  • You can use this guideline to maintain a modeling language subset in high-integrity projects.

Industry Standards

  • IEC 61508-3, Table A.3 (3) 'Language subset'

  • IEC 62304, 5.5.3 - Software Unit acceptance criteria

  • ISO 26262-6, Table 1 (1b) 'Use of language subsets'

  • EN 50128, Table A.4 (11) 'Language Subset'

  • EN 50657, Table A.4 (11) 'Language Subset'

  • DO-331, Section MB.6.3.2.b 'Low-level requirements are accurate and consistent'

Version History

Introduced in R2010a

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See Also

Topics