Scientific publications

Supervisor synthesis is a means to algorithmically derive a supervisory controller from a discrete-event model of a system and a requirements specification. For large systems, synthesis suffers from state space explosion. To mitigate this, synthesis can be applied to a symbolic representation of the models by using Binary Decision Diagrams (BDDs).

For software maintenance and evolution, insight into the codebase is crucial. One way to enhance insight is the application of static analysis to extract and visualize program-specific relations from the code itself, such as call graphs and inheritance trees. Yet, software often contains in-house libraries: unique, domain-specific libraries whose usage is typically scattered throughout the codebase.

The systems being developed by the high-tech industry do not operate in isolation. They are combined with other systems to provide value to their owners. This report is concerned with an important type of systems of systems of which high-tech systems are a part, namely manufacturing systems (of systems).

The Systems Modeling Language (SysML) is a widely used standard for systems engineering, supported by INCOSE and OMG, that provides tools for specifying system structure and behavior through diagrams like block diagrams, use cases, and state machines. The upcoming release of SysML v2 introduces significant improvements, including a graphical and textual syntax, a standardized API for model exchange, and enhanced extensibility for domain-specific extensions.

Structural comparison of state machine models – such as labeled transition systems and (extended) finite automata – is used for numerous applications, such as finding potential behavioral regressions in new oftware versions, evaluating the accuracy of different model learning algorithms, and fingerprinting software for security applications.

The diagnosis of complex systems benefits greatly from a differential, multistep approach that narrows down the list of possible conditions or failures that share the same observable effects to a single root cause. We provide a suitable and practically applicable methodology for this. In extension to existing work, it covers all types of diagnostic actions, i.

Software developers often use logs to, e.g., investigate bugs, familiarize themselves with the underlying system, or improve performance. To do so, they commonly rely on text editors or their own scripts. This lack of appropriate tooling remains a primary challenge in the industrial application of log analysis (state-of-the-practice), despite many tools and techniques proposed by previous scientific studies (state-of-the-art).