Frank Leymann (25 September 1957 in Bochum) is a German computer scientist and mathematician. He is professor of computer science at the University of Stuttgart, Germany, and director and founder of the Institute of Architecture of Application Systems (IAAS).
Biography Leymann studied Mathematics, Physics and Astronomy, and received a Master of Science degree in mathematics (i.e. Dipl.-Math.) in 1982 from University of Bochum, Germany. He worked as research staff member in the Faculty of Mathematics at University of Bochum, where he obtained his PhD in mathematics (i.e. Dr. rer. nat.) in 1984. In his PhD thesis he studied foliations on spaces with singularities. After his PhD he went to IBM Research and Development contributing to software products like DB2, Websphere, or MQSeries. Leymann was main co-inventor and chief software architect of IBM's business process management and workflow products, and was appointed IBM Distinguished Engineer for this work. In 2004, he was appointed full professor of computer science at University of Stuttgart where he founded the Institute of Architecture of Application Systems. He holds many granted patents in the area of software.
Work Frank Leymann's main contributions are from the domains of workflow systems, service-oriented architecture, cloud computing, pattern languages and quantum computing.
Database management His initial focus was on database technology: In order to simplify queries on relational databases with many tables, Leymann co-developed a universal relation system on top of existing relational database systems. Contributions to architectural aspects of stored procedures and user defined functions followed. The latter resulted in investigating the use of object databases, especially ObjectStore, as the underpinning of other middleware. At this time, developers were quite unfamiliar with object databases, thus, Leymann helped to create tooling to ensure proper performance of corresponding applications.
Business process management & workflow systems Workflow systems support companies in modeling, optimizing, and executing their business processes in computing environments. Several languages have been proposed for modeling business processes, out which two languages are widely supported in industry: one of which is the OASIS (organization) standard Business Process Execution Language (BPEL) that Leymann co-invented and which in turn is based on Web Services Flow Language (WSFL), a language that Leymann authored for IBM; the other language is Business Process Model and Notation 2.0 (BPMN), which Leymann co-author too. Such modeling languages support "programming in the large " and allow splitting high-level logic of control- and data flow within an overall application from its low-level logic implementing elementary business functions; this way, workflow-based applications can be created, that allow changing business processes without having to change the programs implementing individual steps of the process. Often, collections of such steps represent long running transactions, i.e. performed steps must succeed or - in case of an error - must be collectively undone; to support this behavior in business processes Leymann introduced compensating transactions in workflow systemsF. Leymann: Supporting Business Transactions Via Partial Backward Recovery in Workflow Management Systems. In: Proc. BTW'95, 1995. Based on his contributions to IBM's workflow products, Leymann co-authored the seminal book "Production WorkflowF. Leymann, D. Roller: Production Workflow: Concepts and Techniques. PTR Prentice Hall, 2000." that explains how to build scalable and reliable workflow systems.
Service computing The architecture and implementation of workflow systems anticipated many aspects of service-oriented programming like the use of service interfaces, service invoker, or service listener. Consequently, from 2000 on, Leymann helped to define several of the original web service standards like WS-Addressing, WS-Business Activity, BPEL4People, or the Web Services Resource Framework. Especially, aggregation of web services has been addressed by BPEL and WSFL. How the plethora of web service standards fit into an architecture for an enterprise service bus was described in a book on the web service platformS. Weerawarana, P. Curbera, F. Leymann, T. Storey, D.F. Ferguson: Web Services Platform Architecture. Prentice Hall, 2005. co-authored by Leymann.
Cloud computing The work on the web services resource framework had already shown that elements of a computing infrastructure like hardware, operating systems etc. can be perceived as services too - just like software functionality. Consequently, complete applications can be outsource to the cloud, which requires standards and technology to provision and manage applications in such environments: Frank Leymann was initial co-author of OASIS TOSCA a language that allows to specify the structure of applications, their artifacts, and dependencies, as well as the associated operational semantics to automatically provision such applications. Leymann's group at University of Stuttgart built an open source implementation of this standard called OpenTOSCA. Guidelines for building applications that fit properly into the cloud have been derived jointly with industry partners and was published as a vendor-neutral language of cloud computing patterns.Ch. Fehling, F. Leymann, R. Retter, W, Schupeck, P. Arbitter: Cloud Computing Patterns, Springer Wien, 2014. Abstract.
Pattern languages Leymann and his group investigated the use of pattern languages not only in the area of cloud computing but in several other domains like the internet of things, green business processes,A. Nowak, F. Leymann, D. Schleicher, D. Schumm, S. Wagner: Green Business Process Patterns. In: Proceedings of the 18th Conference on Pattern Languages of Programs, PLoP 2011A. Nowak, F. Leymann: Green Business Process Patterns - Part II. In: Proceedings of the 6th IEEE International Conference on Service Oriented Computing & Applications (SOCA 2013) or quantum computing.F. Leymann: Towards a Pattern Language for Quantum Algorithms. In: Proc. QTOP 2019 Abstract. The use of pattern languages to (semi-)automatically rewrite the architecture of softwareJ. Guth, F. Leymann: Pattern-based rewrite and refinement of architectures using graph theory. In: Software-Intensive Cyber-Physical Systems (SICS), Springer Berlin Heidelberg, 2019 has been suggested. Patterns are abstractions of concrete working solutions, but in course of the abstraction process the knowledge about these workings solutions is lost - with the consequence that working solutions are created over and over again when a pattern is applied. To avoid this ineffectiveness, the reuse of concrete solutions has been investigated and worked out.M. Falkenthal, J. Barzen, U. Breitenbücher, Ch. Fehling, F. Leymann: Efficient Pattern Application: Validating the Concept of Solution Implementations in Different Domains. In: International Journal on Advances in Software Vol. 7 (3&4), Xpert Publishing Services, 2014M. Falkenthal, F. Leymann: Easing Pattern Application by Means of Solution Languages. In: Proceedings of the 9th International Conferences on Pervasive Patterns and Applications (PATTERNS), 2017M. Falkenthal, U. Breitenbücher, J. Barzen, F. Leymann: On the algebraic properties of concrete solution aggregation. In: SICS Software-Intensive Cyber-Physical Systems, Springer, 2019 In order to show that pattern languages and corresponding new concepts are applicable outside of computer science, they are regularly applied in the humanities,J. Barzen, F. Leymann: Patterns as Formulas: Patterns in the Digital Humanities. In: Proceedings of the Ninth International Conferences on Pervasive Patterns and Applications (PATTERNS), 2017 especially to the domain of filmsJ. Barzen, F. Leymann: Costume Languages As Pattern Languages. In: Proceedings of Pursuit of Pattern Languages for Societal Change - Preparatory Workshop 2014M. Falkenthal, J. Barzen, U. Breitenbücher, S. Brügmann, D. Joos, F. Leymann, M. Wurster: Pattern Research in the Digital Humanities: How Data Mining Techniques Support the Identification of Costume Patterns. In: Computer Science - Research and Development Vol. 32 (3-4), Heidelberg: Springer, 2016 and musicology.J. Barzen, U. Breitenbücher, L. Eusterbrock, M. Falkenthal, F. Hentschel, F. Leymann: The vision for MUSE4Music. Applying the MUSE method in musicology. In: Computer Science - Research and Development Vol. 32 (3-4), Heidelberg: Springer, 2016
Quantum Computing Quantum computing has the potential to solve problems that are intractable today.National Academies of Sciences, Engineering, and Medicine: Quantum Computing: Progress and Prospects. The National Academies Press, Washington, DC. 2019 But programming quantum computers is very different from programming classical computers.Jack D. Hidary: Quantum Computing: An Applied Approach. Springer 2019. In order to support practitioners building solutions based on quantum computers, Leymann and his group proposed a platform for sharing knowledge about building corresponding applications.F. Leymann, J. Barzen, M. Falkenthal: Towards a Platform for Sharing Quantum Software. Proceedings of the 13th Advanced Summer School on Service Oriented Computing (2019). Within the project PlanQK (which Leymann lead as scientific director) this platform was built. Other work focused on a software engineering method for developing hybrid quantum applications,B. Weder, J. Barzen, F. Leymann, D. Vietz: Quantum Software Development Lifecycle. In: Quantum Software Engineering, Springer International Publishing, 2022 and corresponding development tools supporting the creation of applications even on noisy quantum computers.F. Leymann, J. Barzen: The bitter truth about gate-based quantum algorithms in the NISQ era. In: Quantum Science and Technology, IOP Publishing Ltd, 2020 Also, raising awareness of the quantum security threadJ. Barzen, F. Leymann: Continued Fractions and Probability Estimations in Shor’s Algorithm: A Detailed and Self-Contained Treatise. In: AppliedMath. Vol. 2(3), MDPI, 2022. and associated post-quantum cryptographyJ. Barzen, F. Leymann: Post-Quantum Security: Origin, Fundamentals, and Adoption. In: Trends in Computer Science and Information Technology. Vol. 9(3), Peertechz, 2024. is a key aspect of his work; especially, he is helping companies to become quantum-safe.
Honors and awards Elected Member, European Academy of Sciences and Arts (2025) Fellow, International Artificial Intelligence Industry Alliance (AIIA) (2024) Honorary Professor, TU Wien (2023) Appointment, WSO2 Technology Fellow (2023) Appointment, Kurt Gödel Visiting Professor for Quantum Computing, TU Wien (2020) Appointment, Member of the Expert Council for Quantum Computing of the German Government (2020) Fellow, Asia-Pacific Artificial Intelligence Association (AAIA) (2020) Fellow, Center of Integrated Quantum Science and Technology (IQST) (2019) Elected Member, Academia Europaea (2016) Honorary Doctorate, University of Crete (2015) Appointment, IBM Distinguished Engineer (2000) Honorary Professor, University of Stuttgart (1999) Elected Member, IBM Academy of Technology (1996)
References
External links Leymann's University of Stuttgart homepage