Stateflow Design Details

R2026b
Since R2026b

Metric ID

modeldesign.StateflowMaintainability[slcomp.StateflowDesignDetails]

Description

This metric returns detailed maintainability measurements for each Stateflow® design layer in a unit. The measurements include state count, transition count, decision count, Halstead difficulty, effective lines of code, and the graphical and code operator and operand counts used to compute Halstead difficulty. Use this metric to investigate which specific Stateflow design layers contribute to high complexity in a unit.

Supported Artifacts

This metric collects metric results for Units in the project. To control what the dashboard classifies as a unit, see Categorize Models in Hierarchy as Components or Units.

Computation Details

This metric aggregates measurements from multiple underlying calculations:

Decisions — The metric is a heuristic that estimates the number of Stateflow decisions. The metric returns both graphical decisions (based on graphical connections in the chart) and code decisions (based on the action language code). Graphical decisions count transitions with conditions or non-empty triggers and states minus the default state. Code decisions count MATLAB® decisions in entry, during, and exit actions and short-circuit operations (&& and ||) in transition conditions. The metric ignores states and transitions with syntax errors, transitions with empty triggers, and commented out objects.

Halstead Difficulty — The metric calculates Halstead difficulty based on the number of total and unique operators and operands across both the Stateflow graphical elements and MATLAB action code. Commented objects and unresolved symbols are ignored.

The metric calculates the Halstead difficulty, D, using the equation D=n12×N2n2. n1 is the number of unique operators, N2 is the total number of operands, and n2 is the number of unique operands.

Collection

To collect data for this metric, execute the metric engine with the metric ID.

metric_engine = metric.Engine;
results = execute(metric_engine,"modeldesign.StateflowMaintainability[slcomp.StateflowDesignDetails]")

View the metric result values for a specific unit.

results(1).Value
results(1).ScopeAlias

You can also collect all Stateflow maintainability metrics at once by using the group ID.

results = execute(metric_engine,"modeldesign.StateflowMaintainability[]")
Use the MetricID property of each result to identify which metric the result belongs to.

Results

The metric returns an array of metric.Result objects, one for each unit in the project. Use the Value property of the metric result object to view the metric result values. Use the ScopeId and ScopeAlias properties to identify which unit the result belongs to.

The ScopeAlias property returns the name of the unit.

The Value property returns missing when the unit does not contain any Stateflow design layers. When Stateflow design layers exist, the Value property returns one structure per design layer. Each structure has these fields:

  • CodeDecisions — Number of decision points in the action code

  • CodeTotalOperands — Total number of operands in the action code

  • CodeTotalOperators — Total number of operators in the action code

  • CodeUniqueOperands — Number of distinct operands in the action code

  • CodeUniqueOperators — Number of distinct operators in the action code

  • EffectiveLinesOfCode — Number of effective lines of code in the design layer

  • GraphicalDecisions — Number of graphical decision points in the chart

  • GraphicalTotalOperands — Total number of graphical operands

  • GraphicalTotalOperators — Total number of graphical operators

  • GraphicalUniqueOperands — Number of distinct graphical operands

  • GraphicalUniqueOperators — Number of distinct graphical operators

  • HalsteadDifficulty — Halstead difficulty score

  • States — Number of states in the design layer

  • Transitions — Number of transitions in the design layer

  • StateflowElement — Structure identifying the design layer, with fields:

    • Alias — Name of the Stateflow design layer

    • URI — Unique resource identifier for the design layer

  • Decisions — Total number of decision points (code and graphical combined)

  • StateBinEdge — The state count histogram bin that this design layer falls into

  • TransitionBinEdge — The transition count histogram bin that this design layer falls into

  • DecisionBinEdge — The decision count histogram bin that this design layer falls into

  • HalsteadDifficultyBinEdge — The Halstead difficulty histogram bin that this design layer falls into

See Also

Topics