Publications

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).

Usability is a recognized quality of software and complex systems. To investigate relevance of usability methodologies for specialized software tools, this exploratory project surveyed the literature, interviewed three TNO-ESI industry partners on their needs, and scanned the usability knowledge landscape in Dutch universities.

Ensuring safety and security on today’s systems, and systems of systems (SoS), has become a challenge. Systems have become large and complex, they operate in dynamic context and face an ever-changing threatlandscape. Realistically, potential hidden weaknesses and residual flaws must be expected in an SoS, potentially causing undesired emergent behavior.