Automatic instantiation of abstract tests on specific configurations for large critical control systems
This addresses the verification challenge for engineers in critical control systems like railways, though it appears incremental as it automates an existing manual process.
The paper tackles the problem of manually instantiating abstract tests for large critical control systems, which is time-consuming and error-prone, by presenting an automated methodology that has been applied to a railway interlocking system, demonstrating feasibility and effectiveness over several years of testing.
Computer-based control systems have grown in size, complexity, distribution and criticality. In this paper a methodology is presented to perform an abstract testing of such large control systems in an efficient way: an abstract test is specified directly from system functional requirements and has to be instantiated in more test runs to cover a specific configuration, comprising any number of control entities (sensors, actuators and logic processes). Such a process is usually performed by hand for each installation of the control system, requiring a considerable time effort and being an error prone verification activity. To automate a safe passage from abstract tests, related to the so called generic software application, to any specific installation, an algorithm is provided, starting from a reference architecture and a state-based behavioural model of the control software. The presented approach has been applied to a railway interlocking system, demonstrating its feasibility and effectiveness in several years of testing experience.