CFPNlib

Enabling Context-oriented Programming and variability management in Modelica with CFPNlib: The Context Feature Petri Nets Library.

Introduction

The CFPNlib is used to construct the Control Layer that manages variability, dynamically configuring the Modelica modules in the System Layer based on predefined rules and conditions. This layered approach provides a clear separation between control logic (CFPNlib modules) and system dynamics (Modelica models), enabling efficient management of complex systems with variable configurations.

Diagram 1: The CFPNlib-based control logic to manage dynamic mode switching in the system.

Diagram 2: A layered architecture where the CFPNlib Control Layer dynamically configures Modelica models in the System Layer.

Structure:

CFPNlib
|-- Components
	|-- CFPNCore
		|-- DiscretePlace
		|-- TimeEventTransition
		|-- ConditionEventTransition
		|-- InhibitorArc
	|-- ContextPN
		|-- ContextPlace
		|-- ContextPlaceNested
		|-- ContextTransitionTimeEvent
		|-- ContextTransitionConditionEvent
	|-- FeaturePN
		|-- FeaturePlace
		|-- FeaturePlaceNested
		|-- FeatureTransitionTimeEvent
		|-- FeatureTransitionConditionEvent
|-- Examples
	|-- SmartHome 
		(Example using ContextPlace and ContextTransitionTimeEvent for context management)
	|-- CoffeeMaker 
		(Example using FeaturePlace and FeatureTransitionConditionEvent for feature management)
	|-- GreenIT 
		(Example using ContextPlaceNested and ContextTransitionConditionEvent for hierarchical context management)

Functionality

1. Variability Management: Enables flexible management of system variability through Contexts and Features, allowing distinct behaviors or states based on conditions or triggers.

2. Priority Handling: Supports priority-based transitions, ensuring that higher-priority actions are executed first, especially useful for resolving conflicts or critical operations.

3. Nested Contexts and Features: Allows hierarchical management with nested contexts and features, enabling fine-grained control over complex, multi-level systems.

4. Conflict Resolution: Provides conflict-handling mechanisms, including Inhibitor Arcs, to enforce mutual exclusivity and prevent undesired simultaneous actions within system states or features.

5. Separation of Concerns: Promotes better modularization and readability for complex models, making it easier to manage, expand, and understand large systems with distinct functional areas or operational modes.