Verifiable Executable Models for Decomposable Real-time Systems

Abstract

Formally verifiable, executable models allow the high-level design, implementation, execution, and validation of reliable systems. But, unbounded complexity, semantic gaps, and combinatorial state explosion have drastically reduced the use of model-driven software engineering for even moderately complex real-time systems. We introduce a new solution that enables high level, executable models of decomposable real-time systems. Our novel approach allows verification in both the time domain and the value domain. We show that through 1) the use of a static, worst-case execution time, and 2) our time-triggered deterministic scheduling of arrangements of logic-labelled finite-state machines (LLFSMs), we can create succinct Kripke structures that are fit for formal verification, including verification of timing properties. We leap further and enable parallel, non-preemptive scheduling of LLFSMs where verification is feasible as the faithful Kripke structure has bounded size. We evaluate our approach through a case study where we fully apply a model-driven approach to a hard time-critical system of parallel sonar sensors.