Benny Akesson

Senior Research Fellow @ TNO-ESI | Endowed Professor @ University of Amsterdam

TNO-ESI and Academic Partners Deliver ASCI PhD Course on Design and Implementation of Real-time Systems

The Netherlands boasts a world-leading high-tech manufacturing industry renowned for constructing distributed real-time systems of continuously growing complexity. These systems must meet stringent timing requirements to ensure the delivery of mission-critical functionalities. To create interest in the high-tech equipment domain and prepare PhD students in Computer Science to address its performance challenges, TNO-ESI has co-created and delivered a one-week PhD course Design and Implementation of Real-time Systems together with academic partners from Eindhoven University of Technology, University of Twente, and University of Amsterdam. The course is given in the context of the Advanced School for Computing and Imaging (ASCI), a Dutch research school for high-quality research and education in computer systems and imaging systems. ASCI encompasses almost all Dutch universities with computer-science departments. The main goals of ESI involvement in this course were to make participants aware of TNO and its role in society and industry and position it as a possible future employer, and creating awareness of TNO-ESIs vision and work in the area of system performance engineering.

The course is focused on providing an overview of selected timing-sensitive applications and the current research landscape on real-time systems and explaining the rationale behind considering real-time requirements in system software design. Through a series of lectures and hands-on labs, the course covers selected topics from scheduling algorithms, priority assignments, resource sharing, resource reservation, together with their implementation in real-time operating systems. It further discusses emerging challenges and practices in an industrial context, based on empirical surveys and experience from TNO-ESIs applied research on telemetry-based system performance engineering for purposes of performance optimization, verification, and diagnostics.

This first instance of the course was given at the Carlton President Hotel in Maarsen, outside Utrecht between June 10 – 14. 15 PhD students from universities all over the Netherlands researching a broad range of topics in computer science participated in the course. TNO-ESI was in the spotlight during the last day of the course. In the morning, I introduced the high-tech equipment domain and its complexity drivers and explained how new model-based engineering methodologies where needed to address them. Next, my colleague Bram van der Sanden presented our view on the field of System Performance Engineering, along with its focus areas and best practices. This was followed by two concrete examples from our system performance research: Kostas Triantafyllidis presented his work on performance analysis and diagnosis with ASML, followed by a presentation by me about performance verification and conformance checking in microservice systems based on our work with Thales.

The course was well-received by the participants and the contents were rated 8.7/10 in the evaluation. We very much enjoyed the experience of creating and delivering this course together with our academic partners. Thank you Kuan-Hsun Chen (leader of the initiative), Mitra Nasri, and Geoffrey Nelissen for the excellent collaboration in organizing this course. Thanks to Kay Heider and Christian Hakert for leading the hands-on exercises. We are also thankful to invited speakers Bram van der Sanden and Kostas Triantafyllidis.

Reflections on RTAS 2024: A Successful Symposium in Hong Kong

The 30th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2024) is over. As I am enjoying a last local beer at Hong Kong airport before getting on my flight home, it feels like a good opportunity to reflect on this years successful edition of the conference.

The preparation of this conference has taken me, as the Program Chair, about one year. While it was a lot of work, I enjoyed it a lot because I got to work with dedicated, clever, and proactive people from the real-time systems community to make it happen. This year, we received 124 paper submissions from around the world, marking a 40% increase from last year. This suggests that the community is recovering well post-pandemic and there is a clear interest in the topics covered by the conference.

The Program Committee comprised 61 reviewers, supported by 87 sub-reviewers, blending expertise from a diverse group of experts in both academia and industry. Each submission was evaluated through at least four reviews, resulting in a total of nearly 500 double-anonymous expert reviews. Based on these reviews, a brief author response to the reviews to clarify misunderstandings, and online discussions, 29 papers This resulted in an acceptance rate of 23.3%, which means it was very competitive! The accepted papers formed the basis for the outstanding technical program.

Having spent so much time preparing the conference, I really wanted the execution to go smoothly, giving all 100 registered participants a good experience of the technical program. I was happy to see that the preparation had paid off and that there was very little work for me during the conference itself. The session chairs did an excellent job introducing the speakers and managing the sessions. The only curve ball was that one author did not get their visa on time, so we had to quickly improvise a setup for giving remote presentations. This was handled beautifully by the local organizers and I would like to thank Nan Guan and his colleagues for their hard work and attentiveness. From my perspective, the local arrangements worked perfectly!

I was impressed with the quality of the presentations of this edition. Despite the theoretical nature of much of the research, I was pleased to see that presenters managed to focus on their main messages and used lots of figures and animations to get high-level concepts across and referring to the papers for the details. I am asking myself if we, as a community, are getting better at presenting or if this is a side-effect of that we had to reduce the presentation time of the papers from 25 minutes to 18 minutes to fit the increased number of papers in the sessions. Whatever it was, I liked it and hope that this sets the bar for next time!

There were many excellent contributions in the technical program. From Marco Caccamo’s Outstanding Technical Achievement and Leadership Award lecture, we learned that there are many software-based memory management techniques and execution models that can improve the predictability of commercial-of-the-shelf (COTS) multi-processor systems-on-chip and make them suitable for hard real-time or mixed-criticality applications. This is an area where I feel we are making good progress. COTS systems are getting increasingly configurable and observable, allowing our community to propose solutions for real-time systems that do not require custom hardware. This lowers the threshold for transferring our research results to industry significantly.

Looking at the topics addressed at the conference, I was surprised by the large number of papers looking at the intersection of real-time systems and security, so many we needed two sessions to fit all of them! I particularly remember work considering how to ensure control-flow integrity when faced with malicious actors. Two papers looked into how this could be addressed leveraging features recently introduced in COTS platforms. There were also works looking at the effects of performance interference, such as random delays, on cyber-physical systems and how they could be mitigated using robust control strategies in stochastic control systems.

Considering the technical solutions that were presented, I really enjoyed the work by Soni et al. that addressed the scalability of timing analysis of AFDX networks in the avionics domain. The paper proposed a hybrid approach that combined an exact analysis using model checking with a faster and more pessimistic analysis using network calculus. The key idea was to use the bounds provided by network calculus to prune the state space for the model checker to reduce analysis time. I really liked that this hybrid approach worked both ways and allowed the exact analysis done so far by the model checker, to be leveraged by the network calculus to reduce its pessimism. This allowed the proposed analysis to scale to large industrial use cases with more than 1000 network flows.

There is of course a lot more to say about the conference and the papers featured in it, but it is time to fly home.
I want to conclude by thanking all the people that contributed to the organization of the conference. I also want to thank all authors who submitted their work to RTAS 2024. Lastly, I want to thank all conference participants for coming to Hong Kong to listen, learn, discuss, and network. That is what the community is all about!

For more information about RTAS 2024 and the papers featured in its program, please refer to the RTAS 2024 website.

ESI Symposium 2024: A Showcase of Cutting-Edge Research in High-tech Equipment

I had a blast at the ESI Symposium in Veldhoven! It may have been the best ESI Symposium I have visited so far! It is great to see the innovation chain for Dutch high-tech equipment come together and share challenges, exciting new research results, as well as success stories from our implementation partners.

The Symposium also showcased the progress of our academic programs. The Mastering Complexity (MasCot) program, now a veteran at the ESI Symposium, contributes new engineering methodologies to help us manage increasing system complexity and develop next-gen high-tech equipment efficiently and cost-effectively through all development phases, from early architecting to implementation, testing, and evolution. As the program enters its fourth year, the current focus is on rounding off much of the research and transfer developed knowledge and proof-of-concepts to ESI and the industry partners.

The Symposium also introduced our recently started ZORRO project, which is set to change the way we handle system malfunctions in cyber-physical systems. With intelligent diagnostics, ZORRO is on a mission to significantly reduce downtime costs and enhance system reliability. Interested to learn more? Reach out or stay tuned to hear more as the research develops!

Mastering Complexity at ICT.Open

This week saw another edition of NWO ICT.OPEN, a yearly event that brings scientists from all ICT research disciplines and industries together to learn, share ideas, and network.

My colleague Rosilde Corvino and I from TNO-ESI chaired the Mastering Complexity for Cyber-Physical Systems track. This track was kicked off with a keynote about software architecture for strategic advantage, given by Erik Schepers, Chief Software Architect at Thales. Two presentations followed about using large language models to manage software legacy and task-oriented programming for the Internet of Things, respectively. Approximately 30 participants attended the track, highlighting its relevance and the keen interest in cyber-physical systems. The event also saw a few projects from ESI’s Mastering Complexity (MasCot) academic program, DSE2.0 and Software Restructuring, being present with posters.

Lastly, the poster “Models for Legacy Software Systems,” authored by ESI colleagues Joe Reynolds, Nan Yang, Rosilde Corvino, Anca-Maria Lichiardopol, and Joost van Zwam, won the best poster award at the ICT.Open conference. The work has been prized for its innovation, applicability, and clarity of presentation. Congratulations to the team for this achievement, and kudos to Joe Reynolds for his outstanding presentation, demo, and poster explanation.

Next Tuesday, it is time for the next event, the crown jewel of ESI, the ESI Symposium 2024. It is still possible to register for free. I hope to see you there!

Keynote on Managing Variability and Evolution in High-tech Equipment at FOSD Meeting 2024

I had the distinct honor of opening this year’s Meeting on Feature-Oriented Software Development (FOSD Meeting) with a keynote titled “Managing Variability and Evolution in High-tech Equipment”. FOSD Meeting is a yearly informal meeting to bring together the community of researchers working on feature-oriented software development. This year, the event was hosted by TU/e between April 9 – 12.

The keynote covered complexity trends in the high-tech equipment domain, ESI and its role in the high-tech innovation eco-system, and two examples of how variability and evolution were tackled using model-based methodologies at the level of the software architecture in our projects with Thales. The keynote was appreciated by the organizers of the event and the group of 35 participants, mostly from (German) universities but also from ESI’s international applied research partner DLR.

Reflecting on my experience, I was pleasantly surprised at the broad expertise in this community, which covered modelling, software engineering, and performance and I wished I could have stayed around to enjoy the rest of the event. I am happy to see that the keynote triggered some concrete follow ups that can help us link members of this academic community to research in the high-tech equipment ecosystem.

PhD Defense on Governance of Complex Cyber-infrastructure

Today, I chaired a PhD committee at the University of Amsterdam. The PhD candidate Mostafa Mohajeri Parizi defended his dissertation “An Agent-based Approach to the Governance of Complex Cyber-Infrastructures”. The dissertation explores the impact of digitization on society and the need for engineering approaches to ensure that digital systems comply with regulations. Mostafa did his PhD research in the Complex Cyber-Infrastructure (CCI) group under the supervision of TNO colleague Tom van Engers (Principal Scientist ISP DS). The work centers on the use of computational agents and norms to develop tools and methodologies for governing socio-technical systems. The study introduces ASC2, an agent-based programming framework built on the belief-desire-intention model, alongside a scalable multi-agent system environment. It emphasizes the integration of mainstream software development tools into agent-based programming and enhances transparency and decision-making in agents by incorporating context-dependent preferences. Furthermore, the dissertation proposes a modular architecture for integrating norms into multi-agent systems, allowing for the flexible adoption and reasoning of norms without compromising agent autonomy. This is illustrated through two case studies demonstrating the framework’s application in coordinating agent actions and aligning them with encoded laws. The research highlights the potential of agent and norm models in improving the design and policy-making of digital infrastructures.

Mostafa did a good job presenting and defending his work and the committee were impressed by the breadth of the research. We hope the newly minted Dr. Mohajeri Parizi enjoyed the ceremony and the celebration with his friends and family and wish him all the best of luck in his future career.

Performance Engineering in High-Tech Systems: A Visit to CISTER Research Center

I recently had the opportunity to visit the CISTER Research Center for Real-time and Embedded Computing in Porto. It was a great chance to reconnect with former colleagues from my previous tenure there. During my visit, I was invited give a presentation focusing on the complexity challenges in high-tech equipment and ESI’s vision on model-driven performance engineering in this field. The talk also highlighted the growing use of microservice architectures in cyber-physical systems to address the complexity drivers. I explained that while there are good open source tools for instrumenting applications and gathering telemetry data, such as metrics, logs, and traces, new automated analysis methods are needed to reduce the effort of optimizing, verifying, and diagnosing system performance. In this context, I introduced a framework for telemetry-based performance engineering that can be used to address a number of performance challenges. In particular, I explained how it could be used to check whether the system implementation conforms to a UML specification, both in terms of timing and behavior, and to perform performance prediction.

The presentation, which was attended by a group of approximately 15 staff members and PhD students, was well-received and led to fruitful discussions about the relation between real-time systems research and performance engineering. . The visit concluded wonderfully with a delightful dinner with the institute’s director, Prof. Eduardo Tovar, in Matosinhos.

Automatic Workload Inference Improves Scalability of DSE in Complex Systems

I am happy to announce that the paper “Automated Derivation of Application Workload Models for Design Space Exploration of Industrial Distributed Cyber-Physical Systems” has been accepted for publication at the 7th IEEE International Conference on Industrial Cyber-Physical Systems (ICPS). The paper is first-authored by Faezeh Saadatmand in the context of the DSE2.0 project, a part of the academic research program MasCot, co-funded by TNO-ESI and NWO. Congratulations Faezeh!

The paper addresses challenges with respect to designing their next-generation distributed cyber-physical systems (dCPS). Efficient Design Space Exploration (DSE) techniques are needed to evaluate possible design decisions and their consequences on non-functional aspects of the systems. To enable scalable and efficient DSE of complex dCPS, it is essential to have abstract and coarse-grained models that are both accurate and capable of capturing dynamic application workloads. However, manually creating such models is time-consuming and error-prone, and they need to be continuously updated as the system evolves. This research addresses this need by introducing an automatic method for deriving an application workload model. This model, based on trace analysis, captures computation and communication activities within an application in a timing-agnostic manner. The approach has been validated through a case study on an ASML Twinscan lithography machine, demonstrating high accuracy in capturing real application workloads. Next steps in this research involves combining this model with an automatically inferred hardware platform model to enable DSE exploring different hardware, software, and mapping alternatives.

The Journey from Offline to Online Conformance Checking for Microservice Applications

Ricardo Andrade has successfully defended his master thesis “Real-Time Conformance Checking for Microservice Applications“. This thesis was done in the context of the ArchViews project together with Thales. The academic supervisor was ESI colleague and TU/e professor Johan Lukkien and the daily supervision at ESI was done by myself and Ben Pronk.

The thesis addresses the shift from monolithic architectures to microservice architectures in order to manage the complexities and dependencies that emerge as systems grow and incorporate new features. A significant gap identified in the management of microservice applications is the lack of effective conformance checking techniques that can verify whether the execution of microservices aligns with their specification. To address this, the thesis proposes an innovative solution by developing an online conformance checker specifically designed for microservice applications. The project begins with the creation of an offline conformance checker that evaluates conformance using execution traces and sequence diagrams. The work then progresses to an online conformance checker, significantly improving performance and delivering conformance results within approximately 30 seconds per trace. This rapid response time meets the requirement for swift identification and correction of non-conforming sequences, thereby offering a practical and effective tool for managing microservice applications.

Ricardo presented his work very well using beautifully prepared slides. He confidently answered questions from the audience and the examination committee and left the session with a good grade. Ricardo is now moving on from his studies to start his career at CGI. We wish him the best of luck in his future career.

Jesse Liauw-A-Fong Defends Master’s Thesis on Local Anomaly Detection in Smart Public Transport Vehicles

Yesterday, Jesse Liauw-A-Fong, a student of the Master of Software Engineering program at UvA, defended his thesis Local Anomaly Detection in Smart Public Transport Vehicles. This research was conducted externally at a company called Ximedes. Jessie’s research is addressing the problem of detecting anomalies, such as a loss of cloud connection, in Smart Public Transport Vehicles (SPTV), such as buses, trams, and metros, comprising many complex heterogeneous systems. It emphasizes the importance of local, context-aware anomaly detection due to the dynamic nature of SPTVs and explores the generalization of anomaly detection, particularly addressing performance, normal region, and quality challenges. The research proposes a unified data collection framework comparing agent-based and agent-less methods, advocating for an agent-based approach for its adaptability and integration ease. It also quantitatively evaluates three local anomaly detection algorithms on real data from a specific bus line. We thank Jessie for his contributions to our research and wish him the best of luck in his future career.