Literature Review on Network Delay Modelling for Design Space Exploration

Another literature review has been completed in the context of the DSE2.0 research project. William Ford completed his review entitled “Network Delay Model Creation and Validation for Design Space Exploration of Distributed Cyber-Physical Systems“.

Design-space exploration (DSE) in early phases of design of a distributed cyber-physical system (dCPS) requires models. In the DSE2.0 project, we are particularly interested in models that capture the timing behavior of hardware and software, allowing temporal system performance to be evaluated for different design points. One important part of the system to model is the network that connects the subsystems of the CPS. This study reviews previous work in the fields of analytical network modeling, network simulation, and network model validation. In addition, a recommended plan is presented to create and validate such a network model for the DSE2.0 project, based on this previous work. Two main directions are recommended at different levels of abstraction. For the lower level of abstraction, we will make a model using the existing INET framework that models each network element explicitly. At a higher level of abstraction, we will use a latency-rate server to capture the behavior of the network using only two parameters, latency and rate.

Having delivered his literature review. William has started his master project to pursue this research along these directions. The team looks forward to working with him.

Literature Review on Scalable System-level Simulation

Herman Kelder has joined the DSE2.0 research project as a master student. DSE2.0 is a project that aims to propose a methodology for design-space exploration of complex distributed cyber-physical systems, like lithography machines manufactured by ASML. One of the great challenges is to improve the scalability to handle the complexity of such systems, a challenge that needs to be addressed both in terms of how the system (performance) is modelled and evaluated (simulated) for a particular design point, as well as how design points to evaluate is being chosen. Hermans thesis will focus on how to improve the scalability of system-level simulation to allow more design points to be evaluated faster.

One of Herman’s first assignments was to put together a literature review on this topic. The literature review, entitled “Exploring Scalability in System-Level Simulation Environments for Distributed Cyber-Physical Systems“, investigates state-of-the-art scalability techniques for system-level simulation environments, i.e. Simulation Campaigns, Parallel Discrete Event Simulations (PDES), and Hardware Accelerators. The goal is to address the challenge of scalable Design Space Exploration (DSE) for dCPS, discussing such approaches’ characteristics, applications, advantages, and limitations. The conclusion recommends starting with simulation campaigns as those provide increased throughput, adapt to the number of tasks and resources, and are already implemented by many state-of-the-art simulators. Nevertheless, further research has to be conducted to define, implement, and test a sophisticated general workflow addressing the diverse sub-challenges of scaling system-level simulation environments for the exploration of industrial-size distributed Cyber-Physical Systems.

We look forward to working with Herman and seeing how his research develops along these directions.

Mastering Complexity – Academia, Industry and TNO working intimately together

The 3rd Annual Program Day for the Mastering Complexity (MasCot) Partnership program took place on Wednesday October 19. This time, the event was hosted by the University of Amsterdam and was held in the Startup Village at Science Park. Approximately 40 participants from academia, industry, NWO, and TNO attended the event. After a brief introduction, project updates were given from the four academic projects in the program:

  1. Scheduling Adaptive Modular Flexible Manufacturing Systems (SAM-FMS)
  2. Programming and Validating Software Restructurings
  3. TiCToC – Testing in Times of Continuous Change
  4. Design Space Exploration 2.0: Towards Optimal Design of Complex, Distributed Cyber Physical Systems

This was followed by Q&A and a short interaction where participants tried to identify the general complexity management techniques used in the projects. In the afternoon, there were breakout sessions focusing on the way-of-working in MasCot projects, how to best involve and engage all stakeholders in the project: industry and academic partners, users, and ESI liaisons. This allowed the different projects to listen to how the others organized their work, e.g. in terms of regular meetings and working on industry location, during the first years and reflect on the best way-of-working to reach their goals for the next stage.

The event was followed by a social program with informal networking set to the tune of a boat ride with drinks on the beautiful canals of a sunny autumn-colored Amsterdam and a dinner at the restaurant In de Waag.

Position paper accepted at DSD 2022

I am pleased to announce that our position paper “Design Space Exploration for Distributed Cyber-Physical Systems: State-of-the-art, Challenges, and Directions” has been accepted for publication at the Euromicro Conference on Digital System Design (DSD). This is the first accepted paper from the DSE2.0 project, a collaboration between University of Amsterdam, Leiden University, and ASML. The project is a part of the Mastering Complexity (MasCot) partnership program funded by ESI.

The paper addresses the challenge of designing industrial cyber-physical systems (CPS), which are often complex, heterogeneous, and distributed computing systems that typically
integrate and interconnect a large number of hardware and software components. Producers of these distributed Cyber-Physical Systems (dCPS) require support for making (early) design decisions to avoid expensive and time consuming oversights. This calls for efficient and scalable system-level Design Space Exploration (DSE) methods for dCPS. In this position paper, we review the current state of the art in DSE, and argue that efficient and scalable DSE technology for dCPS is more or less non-existing and constitutes a largely unchartered research area. Moreover, we identify several research challenges that need to be addressed and discuss possible directions for targeting such DSE technology for dCPS.

Official Project Kick-off for DSE 2.0

Today was the official project kick-off for the research project “Design Space Exploration 2.0: Towards Optimal Design of Complex, Distributed Cyber Physical Systems”. This project is a part of the Partnership Program Mastering Complexity (MasCot), funded by NWO Domain Applied and Engineering Sciences (AES) together with ESI (TNO). The University of Amsterdam and Leiden University are the academic partners, spearheaded by Andy Pimentel and Todor Stefanov. The carrying industrial partner is ASML, but with Philips, Siemens and ESI as parts of the user committee.

The main goal of the project is to extend existing methods for design-space exploration, often developed for on-chip systems, to cover complex distributed cyber-physical systems (dCPS), such as the lithography machines made by ASML. Designers of such systems need quick answers to so-called “what-if” questions with respect to possible design decisions/choices and their consequences on non-functional properties, such as system performance and cost. This calls for efficient and scalable system level design space exploration (DSE) methods that integrate appropriate application workload and system architectures models, simulation and optimization techniques, as well as supporting tools to facilitate the exploration of a wide range of design decisions. However, such DSE technology for complex dCPS does currently not exist. This projects hence tries to answer the question of how perform efficient and effective DSE for complex, distributed cyber-physical systems.

In today’s kick-off meeting, all stakeholders in the project had an opportunity to introduce themselves and refamiliarize themselves with the project and its goals. The two PhD students who will be working on the project, Marius and Faezeh, from UvA and Leiden, respectively, also gave a brief overview of the work they had done in the first three months of the project, which included a literature review and generation of high-level simulation models for different parameter settings.

I am directly involved in this project through my part-time appointment at UvA. As Marius’ second promotor, I will help him on his journey towards a PhD. I also have an interest in this project as an ESI Research Fellow and part of the MasCot Core Team. In this capacity, I am happy to help linking this project to ESI’s applied research projects, in particular at ASML, to exploit possible synergies, and to stimulate exchanges with other projects in the MasCot program.