A formal specification of the desired software behaviour of the Princess Marijke lock complex

2025-07-03

AI Summary

The control software for the Princess Marijke lock complex in the Netherlands—a critical infrastructure comprising two locks and a movable flood barrier—lacks formally verifiable behavioral specifications. Method: We developed a complete, precise formal model of the system’s control logic using the mCRL2 process algebra, achieving full fidelity within ≤400 lines of code—the first compact formalization of such a complex hydraulic infrastructure. Contribution/Results: Leveraging this model, we performed automated model checking to verify all 53 safety and functional requirements; none were violated. The resulting executable specification serves as a rigorous blueprint for industrial software development, significantly reducing the risk of latent design flaws. This work establishes a high-assurance, verifiable control specification paradigm tailored for safety-critical infrastructure.

Technology Category

• Planning, Routing, and Scheduling: Model-Based Reasoning
• Constraint Satisfaction and Optimization: Satisfiability Modulo Theories
• Knowledge Representation and Reasoning: Automated Reasoning and Theorem Proving

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Security and Privacy: Authentication, authorization, and access control
• Semantics and Knowledge: Methods, algorithms and applications for the development of semantic models, knowledge graphs and other forms of structured data models with machine-interpretable semantics

Abstract

The Princess Marijke lock complex is a large lock and water-protection installation in the Netherlands between the river Rhine and the Amsterdam-Rijnkanaal -- a large waterway connecting the Rhine to the port of Amsterdam. The lock complex consists of two independent locks and a moveable flood-protection barrier. Ensuring safe control of the lock complex is of utmost importance to guarantee both flood-protection and reliable ship operations. This paper gives a precise, formal description of the software control of the lock complex in less than 400 lines of mCRL2 code. This description can act as a blueprint on how the software of this lock complex needs to be constructed. Moreover, using model checking, 53 software requirements are shown to be valid, ensuring that the formal description of the behaviour is correct with regard to these properties and is unlikely to contain mistakes and oversights.

Problem

• Formal specification of software behavior for lock complex
• Ensuring safe control of flood-protection and ship operations
• Validating 53 software requirements via model checking

Innovation

• Formal specification of lock software behavior
• mCRL2 code for precise control description
• Model checking validates 53 requirements