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

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.

Advancing Design Space Exploration: Literature Review Explores Network Delay Models for Distributed Cyber-Physical Systems

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.