Praise for the Third Edition: "This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented."IIE Transactions on Operations EngineeringThoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than presenting a narrow focus on the subject, this update illustrates the wide-reaching, fundamental concepts in queueing theory and its applications to diverse areas such as computer science, engineering, business, and operations research.This update takes a numerical approach to understanding and making probable estimations relating to queues, with a comprehensive outline of simple and more advanced queueing models. Newly featured topics of the Fourth Edition include:Retrial queuesApproximations for queueing networksNumerical inversion of transformsDetermining the appropriate number of servers to balance quality and cost of serviceEach chapter provides a self-contained presentation of key concepts and formulae, allowing readers to work with each section independently, while a summary table at the end of the book outlines the types of queues that have been discussed and their results. In addition, two new appendices have been added, discussing transforms and generating functions as well as the fundamentals of differential and difference equations. New examples are now included along with problems that incorporate QtsPlus software, which is freely available via the book's related Web site.With its accessible style and wealth of real-world examples, Fundamentals of Queueing Theory, Fourth Edition is an ideal book for courses on queueing theory at the upper-undergraduate and graduate levels. It is also a valuable resource for researchers and practitioners who analyze congestion in the fields of telecommunications, transportation, aviation, and management science.

Fundamentals of Queueing Theory

Business Process Management (BPM) includes methods, techniques, and tools to support the design, enactment, management, and analysis of operational business processes. It can be considered as an extension of classical Workflow Management (WFM) systems and approaches. Although the practical relevance of BPM is undisputed, a clear definition of BPM and related acronyms such as BAM, BPA, and STP are missing. Moreover, a clear scientific foundation is missing. In this paper, we try to demystify the acronyms in this domain, describe the state-of-the-art technology, and argue that BPM could benefit from formal methods/languages (cf. Petri nets, process algebras, etc.).

Business Process Management: A Survey

Service Operations Management: Improving Service Delivery

Simulation modeling is widely used to support decision-making in different business areas and management tasks. Given the growing importance for real-world organizations to improve Information Technology Service Management (ITSM), this paper focuses on the application of these techniques to support decision-making in this field. A review of published research articles that describe an application case has been conducted and it shows that different simulation approaches are extensively used to solve particular problems in the context of several processes. However, in these works there is no evidence of a systematic use of both ITSM frameworks and simulation model development methodologies. Given their importance to build valid simulation models, this paper proposes a novel decision-making framework whose main component is a specific methodology to systematically build simulation models that help solve real-world organization problems applying ITIL recommendations. To illustrate the usefulness of this framework, two application cases in the context of the ITIL capacity management and incident management processes are summarized. The model simulations provide information about the process results, performance and behavior with different process configurations. Moreover, optimization experiments allow managers to determine the optimal process configuration that meets the established objectives. A review of research papers that apply simulation modeling in an ITSM context is presented.A decision-making framework to improve ITSM focused on simulation modeling is proposed.The framework main component is a specific simulation model development methodology.Two application cases of the framework in the field of ITIL processes are presented.The ITIL processes analyzed are capacity management and incident management.

Decision-making in IT service management

Event processing networks emerged as a paradigm to implement applications that interact with distributed, loosely coupled components. Such a network consists of event producers, event consumers, and event processing agents that implement the application logic. Event processing networks are typically intended to process an extensive amount of events. Hence, there is a need for performance and scalability evaluation at design time. In this paper, we take up the challenge of modelling event processing networks using coloured Petri nets. We outline how this type of system is modelled and illustrate the formalisation with the widely used showcase of the Fast Flower Delivery Application (FFDA). Further, we report on the validation of the obtained coloured Petri net with an implementation of the FFDA in the ETALIS framework. Finally, we show how the net of the FFDA is employed for analysis with CPN-Tools.

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Net-based analysis of event processing networks: the fast flower delivery case

Due to a steadily increasing market for IT services, providers need to set apart from their competitors in order to successfully assert with their service offerings in the market As a result the improvement of the quality of service process provisioning is becoming a major aspect In this paper we propose a Petri-net based approach in order to model and simulate service processes in terms of availability levels Supported by a tool service providers can perform a priori estimations during design time on the potential impact and interaction of availabilities of services involved in provisioning processes We additionally show how obtained results can be taken into account for negotiating availability levels in Service Level Agreements (SLA)

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Simulation of IT Service Processes with Petri-Nets

Because of a steadily increasing market for IT services, providers need to set apart from their competitors in order to successfully assert with their service offerings in the market. As compliance with negotiated service levels is becoming more and more important for service providers, the improvement of the quality of operational IT service support processes is coming to the fore. In this paper we present an approach based on discrete-event simulation in order to do a priori estimations on ticket workloads within a skills-based IT service desk. Service providers can perform tool-supported capability planning (analysis & optimization) during design time based on the potential impact of ticket workloads to agreed service levels. We additionally show how obtained results can be taken into account for determining service levels in Service Level Agreements (SLA).

Christian Bartsch

Papers

Simulation of IT Service Processes with Petri-Nets

Simulation Environment for IT Service Support Processes: Supporting Service Providers in Estimating Service Levels for Incident Management