Correct-by-construction requirement decomposition

TL;DR

This paper presents a formal, correct-by-construction methodology for decomposing complex system requirements into precise sub-requirements, enhancing safety-critical systems engineering through systematic verification.

Contribution

It introduces a novel formal decomposition approach for contract-based design that guarantees correctness and integrates reachability analysis with constraint programming.

Findings

Improves requirement traceability and manageability in safety-critical systems

Demonstrates effectiveness through a cruise control system case study

Enhances requirement verification and validation processes

Abstract

In systems engineering, accurately decomposing requirements is crucial for creating well-defined and manageable system components, particularly in safety-critical domains. Despite the critical need, rigorous, top-down methodologies for effectively breaking down complex requirements into precise, actionable sub-requirements are scarce, especially compared to the wealth of bottom-up verification techniques. Addressing this gap, we introduce a formal decomposition for contract-based design that guarantees the correctness of decomposed requirements if specific conditions are met. Our (semi-)automated methodology augments contract-based design with reachability analysis and constraint programming to systematically identify, verify, and validate sub-requirements representable by continuous bounded sets -- continuous relations between real-valued inputs and outputs. We demonstrate the efficacy and practicality of a correct-by-construction approach through a comprehensive case study on a cruise control system, highlighting how our methodology improves the interpretability, tractability, and verifiability of system requirements.