Debugging Models

Hans Vangheluwe - University of Antwerp

March 23, 2018, 2:30 p.m. - March 23, 2018, 3:30 p.m.


Hosted by: Jörg Kienzle

One of the main challenges in software and systems engineering is the development and maintenance of complex systems. Model-Based Systems Engineering (MBSE) is a development paradigm that copes with complexity by using models, representing pertinent parts or aspects of the developed systems.

One major benefit of MBSE is to facilitate the early verification and validation (V&V) of systems by checking whether the models representing a system satisfy the set of properties defined in their requirements specification.
To check that a model satisfies its properties, a wide range of V&V techniques are available, such as testing, theorem proving, symbolic execution, model checking, and (real-time) simulation.
These techniques are able to detect the existence of failures in models, i.e., imperfections causing violations of the properties that must be fulfilled. Once the existence of a failure has been detected, the location of the failure (a defect) in the model must however still be identified, and the defect itself must still be removed.  The use of proper debugging techniques is crucial to help in finding and fixing the cause of the problem.

In systems implemented using program code, interactive debugging techniques are commonly used by developers to find a defect by inspecting and manipulating the execution trace leading up to it. For example, interactive debugging techniques can be used to step through the code, put breakpoints (automatic pauses) in strategic locations, inspect and modify local variables, and much more. Other techniques allow partially or fully automated fault location, such as delta debugging and program slicing, as well as automatic repair.

Unfortunately, although program debugging techniques are well established and in common use in both academia and industry, and while verification and validation techniques have found their way into MBSE processes, very few debugging techniques have been proposed for models.

This talk will demonstrate how model debugging can be supported for a wide variety of modelling formalisms.  The approach taken is to model these formalisms explicitly and subsequently instrument their operational semantics with debugging constructs.

Hans Vangheluwe is a Professor in the Antwerp Systems and software Modelling (AnSyMo) group within the department of Mathematics and Computer Science at the University of Antwerp in Belgium, where he is a founding member of the NEXOR IOF consortium on Cyber-Physical Systems (CPS). He is an Adjunct Professor in the School of Computer Science at McGill University, Montreal, Canada. AnSyMo is a Core Research Lab of Flanders Make, the strategic research centre for the Flemish manufacturing industry.  He heads the Modelling, Simulation and Design Lab (MSDL), distributed over the University of Antwerp and McGill.

In a variety of projects, often with industrial partners, he develops and applies the model-based theory and techniques of Multi-Paradigm Modelling (MPM) in diverse application domains.  The adapID IWT-SBO project for example (funded by the Flemish government) investigated how the Belgian electronic ID card can be made more secure and privacy preserving. In the NECSIS project (funded by the Automotive Partnership Canada), he worked on making model transformation industrially usable and analysable. Some of his earlier work has led to the commercial WEST++ tool, which is used world-wide to design and optimize bioactivated sludge Waste Water Treatment Plants.  The MSDL's tool AToM3 (A Tool for Multi-formalism and Meta-Modelling), developed in collaboration with Prof. Juan de Lara of the Autonoma de Madrid uses meta-modelling and graph transformation to specify and generate domain-specific environments. AToMPM, a web-based successor, and its Modelverse kernel are currently under development to support concurrent engineering of CPS.

He was the co-founder and coordinator of the EU ESPRIT Basic Research Working Group 8467 "Simulation in Europe'', a founding member of the Modelica ( Design Team, and an advisor to national and international granting agencies in Europe and North America. He is the chair of the EU COST Action IC1404 Multi-Paradigm Modelling for Cyber-Physical Systems (MPM4CPS).