Author: Benny Akesson

What if we could develop the next-generation of cyber-physical systems with all the bells and whistles faster and more cost-effectively than the previous, while still ensuring that they work correctly? Well, the truth is that industrial cyber-physical systems, such as lithography machines, x-ray machines, production printers, radars, and cars, are getting increasingly complex and difficult to efficiently design, implement, and evolve. Addressing this complexity through new design methodologies has been the common denominator throughout my research career, spanning almost two decades and including both fundamental research in academia and applied research in the Dutch high-tech systems industry. I believe that model-based design methodologies are key to addressing complexity and have many years of experience modelling hardware and software at different levels of abstraction and in a variety of formalisms and use them to generate artifacts, such as code or documentation, or analyze and optimize non-functional properties of systems, such as timing behavior or energy consumption. I enjoy the puzzle of looking at industry challenges, and defining and leading the research needed to address them through a combination of fundamental and applied research projects and programs. I also love working with people and organizations to sustainably embed the developed knowledge and technology, both in industry and academia, turning research results into impact and managing complexity step by step.

MOANA-CBS Milestone at Thales

Posted on by Benny Akesson

It is a fantastic feeling when research results in industry impact! We recently celebrated that our course Modelling and Analysis of Component-based Systems (MOANA-CBS) was given for the 10th time at Thales. We celebrated this milestone with an appropriately themed cake. In total, about 100 systems and software engineers have now been trained in specification and verification of software interfaces using Eclipse CommaSuite. Hats of to our Thales trainers, Jeroen Kouwer and Mark Horsthuis, who are giving the trainings. The word on the street is that seats for the course are still filling up quickly and that more instances of the course are to be expected in the future.

It is not only engineers at Thales that benefit from MOANA-CBS. We also made an academic version of the course that focuses on modelling and verification of software interfaces using Petri nets, allowing students to learn some basics of model-based engineering using examples from the world of systems and software engineering. This material is given as a part of my course Model-based Design of Cyber-physical Systems, which is given to approximately 80 software engineers at University of Amsterdam every year. By now, more than 300 students have learned from this material.

The MOANA-CBS course is a result from the DYNAMICS project, a public-private collaboration between Thales and TNO-ESI that ran between 2019-2021. For more information about the the project and a demo, please read more here.

Paper on Energy Labeling of Digital Services Accepted at CCGRID 2025

Posted on by Benny Akesson

Congratulations to Saeedeh Baneshi for having her paper, “Empowering Sustainability: Energy Labeling of Digital Services Using Simulation” accepted at the 25th IEEE International Symposium on Cluster, Cloud, and Internet Computing (CCGRID).

This work addresses the challenge of creating awareness about the energy consumption of digital services distributed across the compute continuum in an understandable and actionable way. The paper proposes the first operational energy labeling method for digital services in this context. This approach enables stakeholders—including cloud and network providers, application developers, researchers, and end-users of digital services—to better understand and improve the energy efficiency of their applications. Focusing on a video surveillance application and utilizing the enhanced iFogSim framework, the paper proposes an energy labeling scheme and demonstrates its merits through extensive scenario analysis and simulation. It also discusses how this approach can help reduce energy consumption and/or improve performance, without modifying the application’s functional parameters or system architecture.

Congratulations on the acceptance of your paper, Saeedeh. Enjoy the conference in Tromsø, Norway!

 

 

 

William Ford Successfully Defends Master Thesis on Network Delay Models for dCPS

Posted on by Benny Akesson

On Wednesday, William Ford, a master student from VU/UvA defended his master thesis “Network Delay Model Creation and Validation for Design Space Exploration of Distributed Cyber-Physical Systems“. This thesis was executed in the context of the MasCot project DSE2.0 and was supervised by Benny and Faezeh Sadat Saadatmand, PhD student at Leiden University.

William’s thesis focuses on improving the development process of complex distributed cyber-physical systems (dCPS), such as the equipment developed by high-tech companies like ASML, Canon Production Printing, and Philips. Building physical prototypes for these systems is complex and costly, so the thesis explores automated and scalable model-based Design Space Exploration (DSE) as a solution. The research addresses the challenge of modeling network delays in dCPS, aiming to create models that balance speed and accuracy for DSE purposes. The methodology includes formalizing network topology and traffic concepts, resulting in an open-source framework for synthetic network generation called GeNSim. Three analytical network delay models—Constant Delay, Constant Bandwidth, and Latency-Rate, and a simulation-based approach using the INET framework—are proposed and evaluated synthetic networks and an industry case study at ASML. The findings reveal that each model has its strengths and weaknesses, with no single model meeting all requirements perfectly. Therefore, a multi-step modeling approach is suggested to leverage the strengths and mitigate the weaknesses of the different models.

William confidently presented his thesis. In particular, the committee was very happy with the Q&A session after the presentation, which resulted in a lively back and forth with interesting questions and answers. Having defended his thesis, William can now apply for his diploma and graduate. We thank William for his contributions to the DSE2.0 research and wish him all the best with his future career.

Final MasCot Program Day Highlights Results, Lessons Learned, and Future Collaborations

Posted on by Benny Akesson

I had a fantastic time hosting the fourth Mastering Complexity (MasCot) Program Day on October 9 at TU Delft. MasCot, a €3M academic program co-funded by TNO-ESI and NWO, addresses the pressing need for new advanced engineering methodologies through four projects covering essential topics, such as design space exploration during early system design, scheduling, verification, and restructuring of evolving software.

The day started with an update from the four academic projects in the program, focusing on updates and new results from the last year. It was interesting to hear a mix of positive results, e.g. new scheduling methods that outperform previous approaches, as well as negative results, a counter-example that demonstrated that further attempts at proving a particular theory were not worthwhile.

In the afternoon, TNO-ESI and industry partners from the projects shared their user stories, in which they reflected on the value of the program and the knowledge and proof-of-concept implementations developed in it. The user stories were positive and included examples of planned and ongoing technology transfer from the projects.

There were also breakout sessions where TNO-ESI, academic staff, industry representatives, and PhD students separately discussed what went well during the organization and execution of the program, and what should be done differently in the future. This feedback will be consolidated in a document describing the lessons learned from the MasCot Program, which will be used as a basis to refining the method for academic collaborations at TNO-ESI. It was clear from the feedback from all groups that everyone appreciated the program and how TNO-ESI brought academia and industry together to solve relevant problems. A main challenge for the future is to better align stakeholders from industry and academia and their different goals, environments, and timelines.

The day program was concluded with an interactive session, structured around our PMCs, where participants worked together to identify interesting research challenges and hot research topics for future academic collaborations. What stood out in terms of challenges was a clear need to address testing and integration challenges, also in the context of microservices. When looking at hot research topics and technological opportunities … you guessed it … safe, explainable, responsible, … , AI for Systems Engineering!

The day concluded with a social program at Stadsbrouwerij De Koperen Kat with a short tour given by the owner and a BBQ buffet with beer tasting. That concluded the fourth, and last MasCot Program Day.

 

Master’s Thesis Explores User Behavior’s Impact on Digital Service Energy Consumption

Posted on by Benny Akesson

Just before the end of summer, Nsidibe Onoyom Bassey, master student at the Vrije Universiteit Amsterdam, has successfully defended her thesis “Impact of Users’ Behavior on Digital Service Energy Consumption“. Congratulations on the defense and completing your studies Nsidibe!

This work was supervised by Ana Lucia Varbanescu and myself in the context of our research project Energy Labels for Digital Services, which studies the energy consumption of applications distributed over the compute continuum. In particular, the research addresses the growing concerns over energy consumption in the ICT sector, which poses challenges to achieving net-zero emissions. While ICT solutions are often seen as efficient and low-cost, their energy impact is significant, particularly due to the high demand for digital services, such as online shopping. Energy consumption in the digital domain is largely driven by hardware, software, and infrastructure, but the role of user behavior in influencing this consumption is often overlooked. The thesis focuses on understanding how user behavior affects energy consumption in digital services, using a commonly used open-source online shop implemented as microservices as a case study. The energy consumption on both the client and server side is studied and experiments are conducted with different client browsers, user interactions, and number of users. Based on the experiments, an analytical model is proposed to estimate the energy impact of user behavior on the server side and recommendations are made to both users and developers for how to limit energy consumption.

Paper on Multi-Application Energy Analysis in Edge Computing Accepted at FMEC 2024

Posted on by Benny Akesson

Good news everyone! Our paper “Analysing Per-Application Energy Consumption in a Multi-Application Computing Continuum” was accepted at the 9th International Conference on Fog and Mobile Edge Computing (FMEC 2024). This paper was first-authored by Saeedeh Baneshi, a PhD student at the University of Amsterdam, and complements her earlier work “Estimating the Energy Consumption of Applications in the Computing Continuum with iFogSim“. Congratulations on another accepted paper Saeedeh!

The paper addresses the challenge of analyzing the energy consumption of applications distributed over edge devices and data centers in the compute continuum. The goal is to enable stakeholders, such as cloud providers, developers, users, and researchers, to improve energy efficiency, optimize resource usage, and reduce the environmental impact of such applications. To this end, the work proposes a fine-grained simulation approach for analyzing application energy behavior in edge/cloud environments, based on the iFogSim framework. The three main contributions of the work are: 1) An extension is proposed to iFogSim’s energy model to also consider the energy consumption of communication, 2) iFogSim’s reporting is improved to collect finer-grained data, an essential improvement for analysis of multi-application scenarios, and 3) The effectiveness of the approach is demonstrated by evaluating different multi-application scenarios and configurations for a distributed video surveillance application.

Call for Papers: Special Issue on Model-Driven System-Performance Engineering for CPS

Posted on by Benny Akesson

I’m honored to serve as Guest Editor for a special issue of IET Cyber-Physical Systems: Theory and Applications focused on Model-Driven System-Performance Engineering for CPS. This issue is a collaboration with Twan Basten (Eindhoven University of Technology), Arvind Easwaran (Nanyang Technological University), and Marilyn Wolf (University of Nebraska-Lincoln).

We invite submissions from both academia and industry across various application domains. If you’re working in this area, consider contributing your research! The submission deadline is November 1, 2024. Feel free to reach out if you have any questions!

Model-Driven System-Performance Engineering for CPS

Submission deadline: Friday, 1 November 2024
Expected Publication Month: June 2025

System performance refers to the amount of useful work done by a system within predefined quality constraints. System performance often brings the competitive advantage for cyber-physical systems in domains like autonomous driving, chip manufacturing and production systems in general, healthcare, the smart grid, precision agriculture, and so on. To meet market demands for product and system quality, system customization, and a low total cost of ownership, systems need to meet ever more ambitious targets relating to system performance. Performance is a cross-cutting system-level concern, with intricate relations to other system-level concerns like quality, cost, energy efficiency, security, reliability, and customizability. Model-driven system-performance engineering (MD-SysPE) for CPS is essential to improve time-to-quality and the cost-performance ratio of complex systems.

This special issue invites any contributions in model-driven system-performance engineering for CPS that are of interest to the academic and industrial CPS community at large. Original research papers, industrial applications and case studies, and surveys on relevant topics are welcome.

Topics for this call for papers include but are not restricted to:

  • Multi-domain modelling, analysis, and optimization of performance aspects
  • Performance views in system architecture
  • Modelling and analysis of trade-offs with other system qualities
  • Modelling and analysis across abstraction levels
  • Design-space exploration methods
  • Synthesis methods targeting performance
  • Scheduling, control in relation to performance
  • Time-predictable (software) execution
  • Data-driven performance analysis and optimization
  • AI methods for performance analysis, optimization, diagnostics
  • Performance monitoring
  • Run-time adaptation and optimization
  • Performance debugging and diagnostics
  • Model learning for performance
  • Performance validation, verification, and testing

Master Thesis Project Leads to Conference Publication on Microservice Architecture Anti-Patterns at SEAA 2024

Posted on by Benny Akesson

I am delighted to announce that our paper, “Graph-based Anti-Pattern Detection in Microservice Applications,” has been accepted for publication at the 50th Euromicro Conference Series on Software Engineering and Advanced Applications (SEAA). This paper stems from Amund Lunke Røhne’s master thesis project, which he conducted as an internship with TNO-ESI under the supervision of myself and Ben Pronk. This achievement showcases how exceptional work by master students can lead to publications in established conferences.

Our paper addresses a significant challenge in the evolution of microservice applications: as the microservice architecture evolves, architectural anti-patterns may emerge. These anti-patterns are challenging to detect and manage due to their informal natural language definitions and the lack of automated tools. To tackle this, we propose an automated methodology for detecting architectural anti-patterns related to microservice dependencies. A key component of this methodology is the novel Granular Hardware Utilization-Based Service Dependency Graph (GHUBS) model, which is automatically inferred from telemetry data. We have formalized three commonly known anti-patterns and developed algorithms to detect them within the GHUBS model. This methodology is supported by an open-source tool that automatically identifies and visualizes these anti-patterns. We validated our approach using both synthetic data and a case study of a popular microservice benchmarking suite, demonstrating successful detection of the formalized anti-patterns.

Congratulations to Amund on the acceptance of your paper! Your work has made both TNO-ESI and the Software Engineering program at the University of Amsterdam very proud!

Merrick Oost-Rosengren Successfully Defends Thesis on Early Component Verification using Colored Petri Nets

Posted on by Benny Akesson

Just before the summer holidays, another master student has finished his project. This time, it is Merrick Oost-Rosengren who successfully defended his thesis “Formal Verification of Components through Mirroring of Coloured Petri Nets“. Parts of this work was done as an internship with TNO-ESI in collaboration with Thales.

This research addresses a challenge in distributed component-based systems, where different components are developed by different teams, perhaps even different organizations, over time. The problem is that when components are ultimately integrated, their interactions may cause deadlocks, livelock, or unbounded memory behavior. Fixing such problems late in the development process is very costly. An alternative approach is to model components, or component interfaces, early in the design process and use model checking to verify the behavior of the component and its interactions. However, we may not know which components it will interact with yet. Perhaps they have not yet been developed?

The thesis addresses this challenge by proposing a methodology and corresponding tool chain, where components as modelled as Colored Petri Nets from which a verification model, a mirror of the component that captures relevant possible behaviors of interacting components, is automatically generated. As a part of the methodology, the thesis proposes a new class of Colored Petri Nets called Mirrorable Open Colored Petri Nets. This class combines features of existing Colored Petri Nets and Open Petri Nets, and also adds extra semantics to allow the component to be mirrored. It also describes methods for mirroring such a net and fusing the mirror with the original component, such that the components and its interactions can be verified using reachability analysis.

We congratulate Merrick on his successful defense and wish him a lovely summer!

Software variability is as relevant as ever as a driver of complexity in high-tech equipment

Posted on by Benny Akesson

Earlier this week, TNO-ESI arranged a webinar with Jacob Krüger, Assistant Professor at Eindhoven University of Technology. In the presentation “Do We Still Need This? Managing Variability in Modern Software Systems” he presented his research on development and evolution of variant-rich software systems. The presentation explained how successful systems are often cloned to create new variants until managing the variability becomes too complex and expensive. It discussed the transition from cloning towards platform-based software architectures and compared the development costs for new features and new variants, respectively, for the two cases, based on empirical data from industry. These insights are valuable to inform decision-making about when adopting a platform-based approach is strategic. However, Jacob also made clear that moving to a platform-based approach introduces its own challenges, such as ensuring software comprehension and quality, analyzing variability, aligning software and hardware release schedules, and deprecation of variable features.

The webinar attracted an audience of approximately 40 people from TNO-ESI, ASML, Thales, Canon, Vanderlande, ThermoFisher, and Radboud University Nijmegen. This strongly suggests that variability is still a main concern both in systems and software engineering that affects all parts of system development, from early architecting to implementation, testing, and evolution. I was thrilled to see that there was a lively discussion with questions and remarks. In retrospect, I wish we would have reserved more time to keep the conversation going. If you would like to discuss your particular variability challenges or ideas with Jacob, feel free to contact him.

TNO-ESI looks forward to arranging more webinars with experts from our eco-system of academic and industry partners in the field of software and system engineering for high-tech equipment.