arXiv subjects

Wolfgang Reisig

Publications and source records attributed to Wolfgang Reisig.

13 recordsLinked to original sources

arXiv2026

Trust by design -- in praise of modularization: a case study

Ensuring that collective adaptive systems remain safe, reliable, and trustworthy requires measures that transcend so far established formal methods, and in particular established verification techniques. In this contribution, we suggest three such measures: (1) conceptual means: runs with locally confined cause and effect of events, (2) temporal logic like verification techniques that respect and exploit such runs, (3) composing system properties from properties of components. This contribution presents a case study which particularly focuses on the benefits of modularization for achieving trust by design. Further work will develop a full-fledged theory for the presented ideas.

cs.SE↗

arXiv2026

Compositionality of Systems and Partially Ordered Runs

In the late 1970s, C.A. Petri introduced partially ordered event occurrences (runs), then called \emph{processes}, as the appropriate model to describe the individual evolutions of distributed systems. Here, we present a unified framework for handling Petri nets and their runs, specifically to compose and decompose them. It is shown that, for nets $M$ and $N$, the set of runs of the composed net $M \bullet N$ equals the composition of the runs of $M$ and $N$.

cs.LO↗

arXiv2025

Towards a fundamental theory of modeling discrete systems

Modeling is a central concern in both science and engineering. However, we need a new fundamental theory to address the challenges of the digital age. In this paper, we first explain why modeling is fundamental and which challenges must be addressed in the digital world. As a main contribution, we introduce the Heraklit modeling framework as a new approach to modeling. We conclude with some general remarks. Future work will involve the correctness of modeling, the notion of information, and the description of invariance in modeling.

cs.SE↗

arXiv2024

Once and for all: how to compose modules -- The composition calculus

Computability theory is traditionally conceived as the theoretical basis of informatics. Nevertheless, numerous proposals transcend computability theory, in particular by emphasizing interaction of modules, or components, parts, constituents, as a fundamental computing feature. In a technical framework, interaction requires composition of modules. Hence, a most abstract, comprehensive theory of modules and their composition is required. To this end, we suggest a minimal set of postulates to characterize systems in the digital world that consist of interacting modules. For such systems, we suggest a calculus with a simple, yet most general composition operator which exhibits important properties, in particular associativity. We claim that this composition calculus provides not just another conceptual, formal framework, but that essentially all settings of modules and their composition can be based on this calculus. This claim is supported by a rich body of theorems, properties, special classes of modules, and case studies.

cs.SE↗

arXiv2024

Essentials of Petri nets

This contribution highlights some concepts and aspects of Petri nets that are frequently neglected, but that the authors consider important or interesting, or that Carl Adam Petri emphasized.

cs.SE↗

arXiv2024

Towards a Theoretical Foundation of Process Science

Process science is a highly interdisciplinary field of research. Despite numerous proposals, process science lacks an adequate understanding of the core concepts of the field, including notions such as process, event, and system. A more systematic framework to cope with process science is mandatory. We suggest such a framework using an example. The framework itself addresses three aspects: architecture, statics, and dynamics. Corresponding formal concepts, based on established scientific theories, together provide an integrated framework for understanding processes in the world. We argue that our foundations have positive implications not only for theoretical research, but also for empirical research, e.g., because hypothesized relationships can be explicitly tested. It is now time to start a discussion about the foundations of our field.

cs.DB↗

arXiv2022

Discrete models of continuous behavior of collective adaptive systems

Artificial ants are "small" units, moving autonomously on a shared, dynamically changing "space", directly or indirectly exchanging some kind of information. Artificial ants are frequently conceived as a paradigm for collective adaptive systems. In this paper, we discuss means to represent continuous moves of "ants" in discrete models. More generally, we challenge the role of the notion of "time" in artificial ant systems and models. We suggest a modeling framework that structures behavior along causal dependencies, and not along temporal relations. We present all arguments by help of a simple example. As a modeling framework we employ Heraklit; an emerging framework that already has proven its worth in many contexts.

cs.AI↗

arXiv2022

Systems Mining with Heraklit: The Next Step

We suggest systems mining as the next step after process mining. Systems mining starts with a more careful investigation of runs, and constructs a detailed model of behavior, more subtle than classical process mining. The resulting model is enriched with information about data. From this model, a system model can be deduced in a systematic way.

cs.SE↗

arXiv2022

Modellieren mit Heraklit: Prinzipien und Fallstudie

Heraklit is an ongoing research program and development project aimed at creating an infrastructure for modeling large-scale, computer-integrated systems. We discuss the key requirements for such models (hierarchies, user view, transformation of informal into formal ideas, schematic models, equal treatment of digital and person-bound processes) and explain how Heraklit supports these requirements. A case study demonstrates the applicability of Heraklit in practice.

cs.SE↗

arXiv2022

Breathing Life into Models: The Next Generation of Enterprise Modeling

Edsger W. Dijkstra has frequently suggested building a "firewall" between the technology- and application-side of computer science. His justification: The methods to attack the computer scientists' formal, mathematical "correctness problem" differ fundamentally from the methods to attack the applicants' informal "pleasantness problem". In this setting, a model is always confined to one side or the other of this wall. This keynote shows that a seamless transition between both sides can be achieved by a framework with architecture, statics, and dynamics as the three pillars of modeling computer-integrated systems. Selected examples justify this framework. It allows to "breath life" into (static) models, and it implies a new understanding of the "pleasantness" of computer-integrated systems, which is well-needed in the age of "digital first".

cs.SE↗

arXiv2022

Towards Axiomatic Foundations for Conceptual Modeling: An Example

Conceptual modeling is a strongly interdisciplinary field of research. Although numerous proposals for axiomatic foundations of the main ideas of the field exist, there is still a lack of understanding main concepts such as system, process, event, data, and many more. Against the background of the tremendously gaining importance of digital phenomena, we argue that axiomatic foundations are needed for our discipline. Besides the general call, we provide a particular case study using HERAKLIT. This modeling infrastructure encompasses the architecture, statics, and dynamics of computer-integrated systems. The case study illustrates how axiomatically well-founded conceptual models may look like in practice. We argue that axiomatic foundations do not only have positive effects for theoretical research, but also for empirical research, because, for instance, assumed axioms can explicitly be tested. It is now time to spark the discussion on axiomatic foundations of our field.

cs.SE↗

arXiv2022

Modularization, Composition, and Hierarchization of Petri Nets with Heraklit

It is known for decades that computer-based systems cannot be understood without a concept of modularization and decomposition. We suggest a universal, expressive, intuitively attractive composition operator for Petri nets, combined with a refinement concept and an algebraic representation of nets and their composition. Case studies show exemplarily, how large systems can be composed from tiny net snippets. In the future, more field studies are needed to better understand the consequences of the proposed ideas in the real world.

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arXiv2020

Modelling service-oriented systems and cloud services with Heraklit

Modern and next generation digital infrastructures are technically based on service oriented structures, cloud services, and other architectures that compose large systems from smaller subsystems. The composition of subsystems is particularly challenging, as the subsystems themselves may be represented in different languages, modelling methods, etc. It is quite challenging to precisely conceive, understand, and represent this kind of technology, in particular for a given level of abstraction. To capture refinement and abstraction principles, various forms of "technology stacks" and other semi-formal or natural language based on presentations have been suggested. Generally, useful concepts to compose such systems in a systematic way are even more rare. Heraklit provides means, principles, and unifying techniques to model and to analyze digital infrastructures. Heraklit integrates composition and hierarchies of subsystems, concrete and abstract data structures, as well as descriptions of behaviour. A distinguished set of means supports the modeler to express their ideas. The modeller is free to choose the level of abstraction, as well as the kind of composition. Heraklit integrates new concepts with tried and tested ones. Such a framework provides the foundation for a comprehensive Systems Mining as the next step after Process Mining.

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