Bridging the Gap: Rethinking Real-Time Systems for Industry Success and Model-Driven Performance Engineering

The real-time systems community is shrinking and needs to bridge the gap between academic research an industry practice. In my pitch at ECRTS, I shared our view on model-driven system performance engineering for cyber-physical systems and encouraged the community increase its scope and take a broader responsibility for timing-related issues in systems to achieve those goals. This means working in more of the focus areas that we have identified in our vision and validated with our industry partners, but also reconsidering some directions in areas where work is already taking place. This means less focus on hard real-time requirements and formal methods and more focus on:

• system-level KPIs instead of meeting deadlines in subsystems
• soft real-time requirements
• timing requirements beyond software
• system performance modelling, model calibration, and model learning
• data-driven performance analysis, optimization, verification, and diagnostics, e.g. using traces

I encouraged the community to have a look at our vision for model-based system performance engineering for industrial cyber-physical systems and asked to think about how they could contribute through their current and future work.

Please have a look at our vision here.

Thanks to Bram van der Sanden, Kuan-Hsun Chen, Mitra Nasri, Geoffrey Nelissen, and Twan Basten for their help preparing the pitch.

An Empirical Survey-based Study into Industry Practice in Real-time Systems @ RTSS 2020

It is my great pleasure to announce that our paper “An Empirical Survey-based Study into Industry Practice in Real-time Systems” has appeared at the 41st IEEE Real-Time Systems Symposium (RTSS). The paper presents results and observations from a survey of 120 industry practitioners in the field of real-time embedded systems. The survey provides insights into the characteristics of the systems being developed today and identifies important trends for the future. The survey aims to inform both academics and practitioners, helping to avoid divergence between industry practice and fundamental academic research.

This work is a dear pet project of mine that has been a long time in the making. Once I joined ESI (TNO), I started reading papers and attending conferences in the modelling community. I came across empirical survey-based research that systematically investigated industry trends, needs and practices, and that studied adoption and perceived benefits and drawbacks of different technologies and methodologies. I immediately found this line of work incredibly useful as it elevated my understanding of what happened in industry from a collection of anecdotes based on conversations with a few people in a few companies to something that could capture the experience of hundreds of people across industrial domains. I also had the feeling that this line of work provided all the citations I needed for the introduction of my papers, as it helped me position my own work on modelling in a broader industrial reality.

Empirical research is an established research direction in social science, but also in technical fields, such as software engineering and to a lesser extent system engineering. However, there was no work like this in the area of real-time systems. I decided to change this and pitched the idea to Rob Davis, Mitra Nasri, and Geoffrey Nelissen and Sebastian Altmeyer during a meeting in Amsterdam in May 2019. They substantially improved on my ideas and did a lot of very good work and almost a year and a half later, the paper is available for you to read. We could not fit everything we had to say into the RTSS paper, so there is also a supporting technical note entitled “A Comprehensive Survey of Industry Practice in Real-time Systems“.

RTSS Session

A separate session was dedicated to this work on the last day of RTSS 2020. The session began with a 25 minute paper presentation, which is available here:

The paper presentation was followed by a panel discussion involving three industry practitioners from the three main industrial domains covered by the survey: Marcelo Lopez Ruiz (Microsoft), representing the consumer electronics industry, Simon Schliecker (Volkswagen), representing automotive, and Stephen Law (Rolls-Royce), providing an avionics perspective. The panel discussed four key questions relating to the survey results:

Q1. What important characteristics of real-time systems highlighted in the survey results are the most relevant with respect to your industry? And what other important characteristics are there that were not picked up by the survey?

Q2. What are the most relevant trends in real-time systems development in your industry now, and looking ahead over the next 10 years?

Q3.  Did anything surprise you in the survey and its results? And why?

Q4. Given the results of the survey, and your own experience, what recommendations would you to give to the academic community? Which areas should we work more or less on? What assumptions should we make or not make?

The opening statements from the panelists related to the four questions was pre-recorded and followed by a live discussion. The pre-recorded part of the panel is available here:

The session finished after one hour, before there was time to take questions from the audience. A separate Zoom room was created for this purpose and to allow the interaction to continue, which it did for another hour! We were very pleased with the interest in this paper and in the session.

Emerging Research Direction

I hope that this work is the first of many empirical research papers in real-time systems. There are many ways to continue with this line of work. First of all, others need to replicate our results to validate that they hold for different populations. For this purpose, we will be happy to transfer the survey we made on SurveyMonkey, such that it can be reused. Secondly, our survey was very broad and covers real-time systems across many application domains. More specific questions could be obtained if the focus was on a single domain, although the main challenge will be finding enough representative participants with a narrow focus. Thirdly, surveys are only one way of conducting empirical research. Another method sometimes used in software engineering is to use interviews, allowing more in-depth questions to be asked. However, the drawback of this method is that it is more time consuming to interview are large number of participants and to encode and analyze the results.

This direction in real-time system research is just emerging and we hope it will grow and become a well-established part of the research conducted in the community. This would help us better understand the industry we are trying to serve and help us close the gap between academic research and industry practice. A first important step is that this direction is recognized by all main conferences and journals in the area of real-time systems and explicitly included in the call for papers. You can play an important part here by helping us communicate the value of empirical research to others in our community and beyond.

Model-based Engineering Dominates Software-Centric Systems Conference

I attended the online edition of Software-Centric Systems Conference (SC2) today. Although I prefer the networking and social aspects of a physical conference, it was nice to enjoy these presentations from the comfort of my couch.

It was interesting to see that most of the conference presentations were related to domain-specific languages (DSLs) in one way or another. There were also presentations about model-based testing and digital twinning. I am not sure if model-based engineering was an intentional theme, or if this is just what is considered interesting in software-centric systems in the Netherlands for the moment. However, this suggests that the applied research into model-based design methodologies done by ESI (TNO) together with its industrial eco-system is highly relevant.

A highlight for myself was the two presentations about the Component Modelling and Analysis (ComMA) DSL. This is not only because it relates to my research on evolvable interfaces, but also because of the main message that the industry can achieve a lot through open innovation in areas that are not their core business, such as specification, verification, and evolution of software interfaces. Great news that ComMA will become open-source in 2021!

Journal Article Presented at ECRTS 2019

Today, Ali presented our Real-time Systems article “Uneven Memory Regulation for Scheduling IMA Applications on Multi-core Platforms” in the Journal-to-conference (J2C) session at ECRTS.

This article addresses the problem of resource sharing in mixed-criticality systems through temporal isolation by extending the state-of-the-art Single-Core Equivalence (SCE) framework in three ways: 1) we extend the theoretical toolkit for the SCE framework by considering EDF and server-based scheduling, instead of partitioned fixed-priority scheduling, 2) we support uneven memory access budgets on a per-server basis, rather than just on a per-core basis, and 3) we formulate an Integer-Linear Programming Model (ILP) guaranteed to find a feasible mapping of a given set of servers to processors, including their execution time and memory access budgets, if such a mapping exists. Our experiments with synthetic task sets confirm that considerable improvement in schedulability can result from the use of per-server memory access budgets under the SCE framework.

Overall, I greatly appreciate that key conferences in the real-time community are starting to allow journal articles to be presented. This increases the exposure of these works that are often longer and better edited. It is also helpful for researchers at the institutes where conference publications are not considered a relevant KPI. You can argue the validity of this reasoning in areas of computer science where conferences are highly competitive with 20-30% acceptance rates, but it is reality for some researchers. An interesting thing with the MODELS conference is that they collaborate with the SOSYM journal such that some accepted articles in the journal gets a full slot at the conference. This is a nice way to highlight good articles and to appreciate the work done by both authors and reviewers.