Self-driving cars, process control systems, automatic pilot avionics, medical monitoring systems, smart cities, and the Internet of Things: welcome to the wonderful world of cyber-physical systems (CPS)!

The world of CPS is all about sensing and receiving information about the environment, processing resulting data, and reacting to and with the environment within given time constraints. Progress in miniaturization and capability delivery contributed to making CPS increasingly relevant, while at the same time resulted in a continuous increase of the overall level of complexity. One challenge that is currently being addressed is about providing a quantifiable degree of safety and security to such complex systems, where traditional development processes based on manual coding followed by lengthy and extensive testing are no longer adequate.

Looking in perspective, CPS can be considered as the evolution of embedded real-time systems and, consequently, as an opportunity to apply earlier experiences to an emerging field. With this book, Roman Gumzej builds on the process and experiment automation real-time language (PEARL), a language conceived in the 1990s, to provide the specification PEARL language, which can be used to program safe and secure distributed CPS.

One appealing aspect of PEARL is its closeness to natural language, making the code readable and understandable even by nontechnical audiences. The proposal of specification PEARL is meant to enable CPS that are “safe by design” through the representation of hardware and software architectures and the use of timed static transition diagrams, to consistently represent the program tasks of any real-time application. Beyond that, a configuration management mechanism is envisioned to allow dynamic system (re-)configuration, and co-simulation is used to test and validate the quality of service properties.

After an initial introduction to the language (chapter 2) and an explanation of the methodology around which specification PEARL is built (chapter 3), the author presents a unified modeling language (UML) profile as a way to illustrate essential semantic concepts (chapter 4), together with a specialized UML safety pattern (chapter 5) that can be used to design safety shells for CPS applications.

Chapter 6 moves from a deterministic dimension to a more holistic one, to address security-related aspects in the fields of sensing and communications, actuation control, feedback, and data storage. The concluding chapter covers the deployment of PEARL models to application prototypes, for execution on specified target architectures, where the use of co-simulation allows for the tuning and verification of temporal properties.

With the methodology proposed, the author succeeds in linking hardware and software properties through a holistic approach, covering important aspects such as functional correctness, timeliness, safety, and security. This is a suggested read for systems designers interested in the identification of viable ways to deliver, and sustain, reliable and secure CPS implementations.