PLEML Library for SysML v2

SysML v2 library for Model-Based Product Line Engineering (MBPLE). PLEML (Product Line Engineering Modeling Language) is an extension for SysML v2 to model product line features, feature trees, feature configurations, and constraints between features.

Source: github.com/mbse4u/pleml

Sysand project: sysand.com/projects/mbse4u/pleml — Sysand is a package registry for publishing, versioning, and discovering reusable SysML v2 libraries.

PLEML is based on the paper by Tim Weilkiens, Marco Forlingieri, and Vince Molnar, "Next Generation MBPLE with SysML v2: Feature Modeling, Variability Modeling, and API Potentials", presented at the INCOSE Symposium 2025: https://doi.org/10.1002/iis2.70058

What's in the Library

PLEML provides the semantic metadata and structural constructs to represent variations, configurations, and constraints of a product line in SysML v2:

• FeatureModel — Container of the feature trees and feature configurations of a product line
• FeatureTree — Hierarchy of features that specifies the variability. Nesting builds the hierarchy, multiplicities model optional and mandatory features, specialization models alternatives
• Feature — Characteristic of a product with name, bindingTime, externalRepresentation (for proxy features), and the derived isAuthoritative
• FeatureConfiguration — Selection of features that describes a member product, verified by built-in constraints (only features, all non-root features set, consistent binding time, all feature constraints satisfied)
• Feature constraints — RequiresConstraint (requiresFeatures) and XORConstraint (xorFeatures, aka conflict constraint), both evaluated against a feature configuration
• LifeCycleKind — Binding times Development, Production, and Operation
• PLEML keywords — #featureModel, #featureTree, #feature, and #featureConfiguration for clean model notation
• Feature bindings — Metadata @FB (FeatureBinding) binds elements of shared assets to features, @FCFGB (FeatureConfigurationBinding) binds a product model to a feature configuration. DeriveFeatureName derives the feature name from a dependency

All elements are documented with doc comments in PLEML.sysml.

Getting Started

Import the library into your SysML v2 model:

package MyProductLine {
    private import PLEML::*;

    #featureModel occurrence def MyFeatureModel {
        #featureTree occurrence myFeatureTree :> featureTrees {
            #feature occurrence optionalFeature[0..1] default null;
            #feature occurrence otherFeature[0..1] default null {
                assert constraint :>> requiresFeatures {
                    in #feature occurrence :>> requiredFeatures = (optionalFeature);
                }
            }
        }
        #featureConfiguration occurrence myProduct :> myFeatureTree, featureConfigurations {
            #feature occurrence :>> optionalFeature[1];
            #feature occurrence :>> otherFeature[1];
        }
    }
}

The Drone product line example shows the complete approach.

Repository Structure

PLEML.sysml                                                    # The PLEML library
Examples/                                                      # Drone Product Line example
  MBPLE-Example-DroneProductLine-PLEML-SysMLv2-FeatureModel.sysml    # Feature tree and feature configurations
  MBPLE-Example-DroneProductLine-PLEML-SysMLv2-SharedAssets.sysml    # Shared assets linked to features
  MBPLE-Example-DroneProductLine-PLEML-SysMLv2-ProductModel.sysml    # Product model of a member product

Tests

Test/PLEML-Test-Constraints.sysml contains valid and violating feature configurations for the XORConstraint and RequiresConstraint, with the expected verdict documented. Evaluating the constraints requires a tool that supports suboccurrences and the binding of the featureConfiguration; OpenSysML v0.9.2 loads the models but does not evaluate the constraints conclusively.

Contributing

Contributions are welcome — please submit issues or pull requests.

Maintainers

• Tim Weilkiens (Contact: tim@mbse4u.com)
• Marco Forlingieri
• Vince Molnar

License

• Copyright Tim Weilkiens, Marco Forlingieri, Vince Molnar
• MIT License — see LICENSE for details.