M. Silva Significant changes have been occurring in industrialized countries since the Second World War. Production is moving towards sophisticated high qUality products, economy of scale has been replaced by economy of scope, jerky demands are progressively replacing steady demands, and competi tiveness is becoming a worldwide phenomenon. These trends require highly automated manufacturing systems with small set-up times and high flex ibility. As a consequence, implementation and running costs of modem manufacturing systems are drastically increasing, whereas their fields of application remain limited, and every day become even narrower, which increases the risk of early obsolescence. This is the reason why designers are trying to improve the preliminary design phase, also known as the 'paper study phase'. The preliminary design phase includes, but is not limited to, the func tional specification, and the evaluation of the system. Many tools exist to support the functional specification of manufactur ing systems. IDEFO is one of these tools. It leads, using a top-down ap proach, to a precise functional description of the required system. However, its use cannot be extended further. In general, the evaluation starts with a modeling step, which depends on the evaluation tool used, and ends by applying the model to find out its main dynamic characteristics. Two main approaches can be used to perform this task, namely simulation and math ematical approach. Using simulation, the modeling tool is either a classical computer language, or a simulation language.

Control of Discrete-event Systems provides a survey of the most important topics in the discrete-event systems theory with particular focus on finite-state automata, Petri nets and max-plus algebra. Coverage ranges from introductory material on the basic notions and definitions of discrete-event systems to more recent results. Special attention is given to results on supervisory control, state estimation and fault diagnosis of both centralized and distributed/decentralized systems developed in the framework of the Distributed Supervisory Control of Large Plants (DISC) project. Later parts of the text are devoted to the study of congested systems though fluidization, an over approximation allowing a much more efficient study of observation and control problems of timed Petri nets. Finally, the max-plus algebraic approach to the analysis and control of choice-free systems is also considered. Control of Discrete-event Systems provides an introduction to discrete-event systems for readers that are not familiar with this class of systems, but also provides an introduction to research problems and open issues of current interest to readers already familiar with them. Most of the material in this book has been presented during a Ph.D. school held in Cagliari, Italy, in June 2011.

Hardware Design and Petri Nets presents a summary of the state of the art in the applications of Petri nets to designing digital systems and circuits. The area of hardware design has traditionally been a fertile field for research in concurrency and Petri nets. Many new ideas about modelling and analysis of concurrent systems, and Petri nets in particular, originated in theory of asynchronous digital circuits. Similarly, the theory and practice of digital circuit design have always recognized Petri nets as a powerful and easy-to-understand modelling tool. The ever-growing demand in the electronic industry for design automation to build various types of computer-based systems creates many opportunities for Petri nets to establish their role of a formal backbone in future tools for constructing systems that are increasingly becoming distributed, concurrent and asynchronous. Petri nets have already proved very effective in supporting algorithms for solving key problems in synthesis of hardware control circuits. However, since the front end to any realistic design flow in the future is likely to rely on more pragmatic Hardware Description Languages (HDLs), such as VHDL and Verilog, it is crucial that Petri nets are well interfaced to such languages. Hardware Design and Petri Nets is divided into five parts, which cover aspects of behavioral modelling, analysis and verification, synthesis from Petri nets and STGs, design environments based on high-level Petri nets and HDLs, and finally performance analysis using Petri nets. Hardware Design and Petri Nets serves as an excellent reference source and may be used as a text for advanced courses on the subject.

The move of manufacturing systems towards automation, integration and flexibility has increased the importance of the design phase in the life cycle of a manufacturing system. Petri Nets are the only set of tools which can support functional specification, modelling and evaluation of the future behaviour of the manufacturing system. This book is dedicated to the use of Petri Nets for specifying, modelling and evaluating the performances of manufacturing systems. The first part of the book presents the theory of Petri Nets, covering most of the recent developments. Applications of Petri Nets to modelling, evaluation and management of manufacturing systems are addressed in the second part. Numerous worked examples and solved exercises are included. Specific algorithms for planning and scheduling are provided. This book will be of great interest to students, factory engineers, managers and designers in both the academic and industrial worlds.

This book presents the definition, validation and application of a selected set of Petri nets. It first introduces the basic models including time and stochastic extensions, in particular place-transition and high level Petri nets. Their modeling and design capabilities are illustrated by a set of representations of interest in operating and communication systems. The volume then addresses the related verification problems and proposes corresponding solutions by introducing the main notions needed to fully understand the behavior and properties behind Petri nets. Particular attention is devoted to how systems can be fully represented and analyzed in terms of their behavioral, time and stochastic aspects by using the same formal approach and semantical basis. Finally, illustrative examples are presented in the important fields of interoperability in telecommunication services, programmation languages, multimedia architectures, manufacturing systems and communication protocols.

Illustrated with real-life manufacturing examples, Formal Methods in Manufacturing provides state-of-the-art solutions to common problems in manufacturing systems. Assuming some knowledge of discrete event systems theory, the book first delivers a detailed introduction to the most important formalisms used for the modeling, analysis, and control of manufacturing systems (including Petri nets, automata, and max-plus algebra), explaining the advantages of each formal method. It then employs the different formalisms to solve specific problems taken from today’s industrial world, such as modeling and simulation, supervisory control (including deadlock prevention) in a distributed and/or decentralized environment, performance evaluation (including scheduling and optimization), fault diagnosis and diagnosability analysis, and reconfiguration. Containing chapters written by leading experts in their respective fields, Formal Methods in Manufacturing helps researchers and application engineers handle fundamental principles and deal with typical quality goals in the design and operation of manufacturing systems.

One critical barrier leading to successful implementation of flexible manufacturing and related automated systems is the ever-increasing complexity of their modeling, analysis, simulation, and control. Research and development over the last three decades has provided new theory and graphical tools based on Petri nets and related concepts for the design of such systems. The purpose of this book is to introduce a set of Petri-net-based tools and methods to address a variety of problems associated with the design and implementation of flexible manufacturing systems (FMSs), with several implementation examples.There are three ways this book will directly benefit readers. First, the book will allow engineers and managers who are responsible for the design and implementation of modern manufacturing systems to evaluate Petri nets for applications in their work. Second, it will provide sufficient breadth and depth to allow development of Petri-net-based industrial applications. Third, it will allow the basic Petri net material to be taught to industrial practitioners, students, and academic researchers much more efficiently. This will foster further research and applications of Petri nets in aiding the successful implementation of advanced manufacturing systems.