Model Maintainability Metrics

R2026b

The Model Maintainability Dashboard helps you analyze the maintainability and complexity of the units and components in your design across the model development lifecycle. The dashboard collects metric data from the model design artifacts in a project, such as MATLAB^® code, Simulink^® models, and Stateflow^® charts. You can also collect these metrics programmatically by using the metric.Engine API.

Use these tables to explore the model maintainability metrics, view their metric IDs, and access information about each metric.

The model maintainability metrics cover these areas:

To collect available model maintainability metrics programmatically, use the getAvailableMetricIds and execute functions.

metricEngine = metric.Engine;
ids = getAvailableMetricIds(metricEngine,App="DashboardApp",Dashboard="ModelMaintainability");
results = execute(metricEngine,ids)

For more information, see Collect Model Maintainability Metrics Programmatically.

If your scripts reference metric IDs from R2026a or earlier, see Migrate from Earlier Metric IDs.

Component Structure and Interfaces

Analyze the structure of a software component, including the hierarchy, ports, and signals.

Metric	Metric ID
Component Structure	`slcomp.ComponentStructure`
Simulink Component Interface	`modeldesign.SimulinkMaintainability[slcomp.ComponentInterface]`
Input and Output Component Interface Signals	`modeldesign.SimulinkMaintainability[slcomp.ConnectedSignals]`

Overall Maintainability

Assess the overall maintainability and complexity of each unit by examining aggregate complexity measures such as design cyclomatic complexity and Halstead difficulty.

Metric	Metric ID
Overall Design Summary	`modeldesign.OverallMaintainability[slcomp.OverallDesignSummary]`

Simulink Maintainability

Assess the maintainability of Simulink design layers by examining complexity measures and the distribution of blocks, decisions, signal lines, and Goto blocks.

Metric	Metric ID
Simulink Design Summary	`modeldesign.SimulinkMaintainability[slcomp.DesignSummary]`
Simulink Design Details	`modeldesign.SimulinkMaintainability[slcomp.SimulinkDesignDetails]`
Simulink Decision Distribution	`modeldesign.SimulinkMaintainability[slcomp.DecisionDistribution]`
Simulink Halstead Difficulty Distribution	`modeldesign.SimulinkMaintainability[slcomp.HalsteadDifficultyDistribution]`
Simulink Block Distribution	`modeldesign.SimulinkMaintainability[slcomp.BlockDistribution]`
Signal Line Distribution	`modeldesign.SimulinkMaintainability[slcomp.SignalLineDistribution]`
Goto Distribution	`modeldesign.SimulinkMaintainability[slcomp.GotoDistribution]`

To collect all of these Simulink maintainability metrics, you can use modeldesign.SimulinkMaintainability[] as the metric ID:

results = execute(metricEngine,modeldesign.SimulinkMaintainability[])

Stateflow Maintainability

Assess the maintainability of Stateflow design layers by examining complexity measures and the distribution of states, transitions, and decisions.

Metric	Metric ID
Stateflow Design Summary	`modeldesign.StateflowMaintainability[slcomp.DesignSummary]`
Stateflow Design Details	`modeldesign.StateflowMaintainability[slcomp.StateflowDesignDetails]`
Stateflow Decision Distribution	`modeldesign.StateflowMaintainability[slcomp.DecisionDistribution]`
Stateflow Halstead Difficulty Distribution	`modeldesign.StateflowMaintainability[slcomp.HalsteadDifficultyDistribution]`
State Distribution	`modeldesign.StateflowMaintainability[slcomp.StateDistribution]`
Transition Distribution	`modeldesign.StateflowMaintainability[slcomp.TransitionDistribution]`

To collect all of these Stateflow maintainability metrics, you can use modeldesign.StateflowMaintainability[] as the metric ID:

results = execute(metricEngine,"modeldesign.StateflowMaintainability[]")

MATLAB Maintainability

Assess the maintainability of MATLAB design layers by examining complexity measures, code size, decision density, and detailed design measurements.

Metric	Metric ID
MATLAB Design Summary	`modeldesign.MATLABMaintainability[slcomp.DesignSummary]`
MATLAB Design Details	`modeldesign.MATLABMaintainability[slcomp.MATLABDesignDetails]`
MATLAB Decision Distribution	`modeldesign.MATLABMaintainability[slcomp.DecisionDistribution]`
Executable Lines of Code Distribution	`modeldesign.MATLABMaintainability[slcomp.ELOCDistribution]`
Halstead Difficulty Distribution	`modeldesign.MATLABMaintainability[slcomp.HalsteadDifficultyDistribution]`

To collect all of these MATLAB maintainability metrics, you can use modeldesign.MATLABMaintainability[] as the metric ID:

results = execute(metricEngine,"modeldesign.MATLABMaintainability[]")

Migrate from Earlier Metric IDs

Since R2026b

Starting in R2026b, the model maintainability metrics use a different naming convention and can return results in improved table-based formats. If you have scripts that call earlier metric IDs, use the tables in this section to identify the replacement metrics.

Migrate Component Structure and Overall Maintainability Metrics

Earlier Metric ID	Replacement Metric ID
`slcomp.OverallCyclomaticComplexity`	`modeldesign.OverallMaintainability[slcomp.OverallDesignSummary]`
`slcomp.HalsteadDifficulty`
`slcomp.LayerDepth`	`slcomp.ComponentStructure`
`slcomp.MaxLayerDepth`
`slcomp.LayerBreadth`
`slcomp.MaxLayerBreadth`
`slcomp.InterfacePorts`	`modeldesign.SimulinkMaintainability[slcomp.ComponentInterface]`

Migrate Simulink Maintainability Metrics

Earlier Metric ID	Replacement Metric ID
`slcomp.SimulinkDecisions`	`modeldesign.SimulinkMaintainability[slcomp.DesignSummary]`
`slcomp.SLCyclomaticComplexity`
`slcomp.SimulinkHalsteadComplexity`
`slcomp.SimulinkHalsteadDifficulty`
`slcomp.SimulinkDecisionDistribution`	`modeldesign.SimulinkMaintainability[slcomp.DecisionDistribution]`
`slcomp.SimulinkHalsteadDifficultyDistribution`	`modeldesign.SimulinkMaintainability[slcomp.HalsteadDifficultyDistribution]`
`slcomp.OverallBlocks`	`modeldesign.SimulinkMaintainability[slcomp.BlockDistribution]`
`slcomp.SimulinkBlocks`
`slcomp.BlocksDistribution`
`slcomp.OverallSignalLines`	`modeldesign.SimulinkMaintainability[slcomp.SignalLineDistribution]`
`slcomp.SimulinkSignalLines`
`slcomp.SignalLinesDistribution`
`slcomp.OverallGotos`	`modeldesign.SimulinkMaintainability[slcomp.GotoDistribution]`
`slcomp.SimulinkGotos`
`slcomp.GotosDistribution`
`sldesignlayer.SimulinkDesignInfo`	`modeldesign.SimulinkMaintainability[slcomp.SimulinkDesignDetails]`

Migrate Stateflow Maintainability Metrics

Earlier Metric ID	Replacement Metric ID
`slcomp.StateflowDecisions`	`modeldesign.StateflowMaintainability[slcomp.DesignSummary]`
`slcomp.SFCyclomaticComplexity`
`slcomp.StateflowHalsteadComplexity`
`slcomp.StateflowHalsteadDifficulty`
`slcomp.StateflowDecisionsDistribution`	`modeldesign.StateflowMaintainability[slcomp.DecisionDistribution]`
`slcomp.StateflowHalsteadDifficultyDistribution`	`modeldesign.StateflowMaintainability[slcomp.HalsteadDifficultyDistribution]`
`slcomp.OverallTransitions`	`modeldesign.StateflowMaintainability[slcomp.TransitionDistribution]`
`slcomp.StateflowTransitions`
`slcomp.TransitionsDistribution`
`slcomp.OverallStates`	`modeldesign.StateflowMaintainability[slcomp.StateDistribution]`
`slcomp.StateflowStates`
`slcomp.StatesDistribution`
`sfdesignlayer.StateflowDesignInfo`	`modeldesign.StateflowMaintainability[slcomp.StateflowDesignDetails]`

Migrate MATLAB Maintainability Metrics

Earlier Metric ID	Replacement Metric ID
`slcomp.MATLABDecisions`	`modeldesign.MATLABMaintainability[slcomp.DesignSummary]`
`slcomp.MATLABCyclomaticComplexity`
`slcomp.MATLABHalsteadComplexity`
`slcomp.MATLABHalsteadDifficulty`
`slcomp.MATLABDecisionsDistribution`	`modeldesign.MATLABMaintainability[slcomp.DecisionDistribution]`
`slcomp.MATLABHalsteadDifficultyDistribution`	`modeldesign.MATLABMaintainability[slcomp.HalsteadDifficultyDistribution]`
`slcomp.OverallMATLABeLOC`	`modeldesign.MATLABMaintainability[slcomp.ELOCDistribution]`
`slcomp.MATLABeLOC`
`slcomp.MATLABeLOCDistribution`
`mldesignlayer.MATLABDesignInfo`	`modeldesign.MATLABMaintainability[slcomp.MATLABDesignDetails]`