This Second Edition presents a practical framework for software development based on Event-B and refinement calculus, showing how formal models can be systematically transformed into verified executable programs. The book guides readers through the complete development process, from the formalisation of software requirements to model refinement, proof discharge, code synthesis, and implementation validation.  The text introduces the Event-B method and its supporting tool ecosystem and demonstrates how refinement-based modelling can be used to construct reliable software systems incrementally. Particular emphasis is placed on the systematic derivation of Java implementations through automated code generation, together with the verification of sequential programs using the newly introduced PyEB framework in Python.  Using a series of detailed case studies, the book illustrates how mathematical modelling techniques reduce ambiguity in requirements, support correctness-by-construction development, and provide rigorous reasoning about program behaviour throughout the software lifecycle.

Nestor Catano, Ph.D., is a faculty member at The University of Algarve, Portugal, in software engineering, computer science, and cybersecurity. He earned his Ph.D. and M.S. in Computer Science from Université Paris Cité, as well as an M.S. in Information and Cybersecurity  from the University of California, Berkeley. Dr. Catano has more than 20 years of teaching experience and has worked as a researcher at universities around the world. His main research area is the use of formal methods for software engineering for safety and security applications, with a focus on refinement calculus and Event-B.