Author: Bruce Silver
Publisher: Cody-Cassidy Press
Publication Date: October 2011
Pages: 236
Overview
BPMN 2.0 is the industry standard diagramming language for business process models. The meaning of a business process diagram remains consistent regardless of the tool used to create it. However, creating models that are correct, complete, and clear demands more than just a dictionary of BPMN shapes and symbols.
This book provides a prescriptive, top-down methodology for turning a blank page into complete process models that adhere to conventions, ensuring your process logic can be translated into unambiguous diagrams—essentially, “good BPMN.” This is achieved through a disciplined approach called “method and style,” which includes conventions that ensure the process logic is unambiguous from the diagram alone.
The first half of the book has been completely rewritten from the first edition, incorporating feedback from hundreds of students in BPMN training. The author explains the elements of BPMN style and the principles of composition which BPMN process modelers need to understand to create models that are not only correct per the BPMN 2.0 specification but also easily understood without the need for attached documentation. This is achieved using a 2-level approach:
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Level 1 (the Descriptive modeling subclass of BPMN 2.0): A palette of shapes and symbols largely carried over from traditional flowcharting.
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Level 2 (the Analytic subclass): Expands the palette to describe event-triggered behavior, critical for modeling exception handling.
The second half of the book, the BPMN Implementer’s Guide, is completely new and addressed to developers and BPMN tool vendors. The Implementer’s Guide focuses on how to correctly serialize BPMN, emphasizing the XML serialization of the diagram for both non-executable and executable process models. It details the BPMN 2.0 metamodel and XML Schema, the Descriptive and Analytic Process Modeling Conformance subclasses, and the BPMN-I Profile, a set of serialization rules that facilitate interoperability of BPMN models in the Analytic subclass between tools.
The guide also explains how BPMN 2.0 describes execution-related details, such as process data and data mapping, services, messages, and human task assignment, illustrated with an example of an executable process. It concludes with guidelines for implementers on how to align executable design with business-oriented top-down process modeling.
The book is lavishly illustrated with over 100 BPMN diagrams, and the BPMN Implementer’s Guide section contains many XML examples that can be used as reference.
Key Learning Objectives
With this book, you will learn three key aspects of BPMN:
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BPMN Vocabulary: The shapes and symbols you need, with a focus on eliminating those you don’t.
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Method: A systematic five-step procedure for turning details from stakeholder workshops and interviews into well-structured BPMN digital asset that communicates clearly to all stakeholders, including other project teams, business, and IT.
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BPMN Style: Conventions designed to ensure the meaning of the process logic is clear from the printed diagrams alone, even to those unfamiliar with BPMN. These conventions are framed as additional rules that are validated in the Trisotech Workflow Modeler.
Topics include:
- What is BPMN?
- Differences from traditional flowcharts
- “Good BPMN”
- Activity and Process: BPMN’s hidden conceptual framework
- Gateways and end states
- Subprocesses and process levels
- Pools and message flows
- Start events and the process instance
- The Method
- The essential style rules
- Parallel flow
- Timer events
- Message events
- Event gateway
- Error events
- Event subprocesses
- Iteration
Preface
BPMN, which stands for Business Process Model and Notation, is a diagramming language for business process models. Its significance lies not in being superior to other process notations, but in its status as a multi-vendor standard, maintained by the Object Management Group (OMG), and its wide adoption by modelers and tool vendors alike. This book goes beyond merely defining BPMN’s shapes and symbols; it introduces a unique approach to understanding and mastering the process modeling standard, based on two fundamental principles:
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The Method and Style Principle: A BPMN diagram should have one and only one interpretation. The process logic should be completely and unambiguously described by the diagram alone.
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The BPMN-I Principle: A BPMN diagram should have one and only one XML serialization. Without this, model interchange between tools cannot be achieved.
The first principle is directed at modelers, while the second targets implementers, such as BPMN tool vendors, yet they are closely intertwined. Unfortunately, strict adherence to the BPMN 2.0 specification alone does not ensure fulfillment of these principles. Meeting these standards necessitates additional conventions, which the Author refers to as style rules and BPMN-I rules, respectively. BPMN Method and Style not only elucidates the meaning and application of crucial diagram elements but also provides prescriptive guidance, including style rules and BPMN-I rules, for constructing BPMN models that are clear, complete, consistent, and interchangeable between tools.
Structure of the Book
BPMN Method and Style
Part 1: What Is BPMN? This section discusses BPMN’s significance in business process management, comparing it to traditional flowcharting and distinguishing between “good BPMN” and “bad BPMN.” It also explores BPMN’s conceptual foundations and how its notions of activity and process relate to business process architecture.
Part 2: Method and Style – Level 1. Here, the Author introduces the Method and Style approach to process modeling. The section begins with “BPMN by Example,” guiding the reader through the construction of a complete process model using a limited set of BPMN shapes and symbols, known as the Level 1 palette. This palette consists of elements familiar from traditional flowcharting. The book then revisits and explains the meaning and proper usage of each Level 1 element.
Next, the Method is presented as a step-by-step guide for creating consistent end-to-end BPMN models that clearly display the process instance, its end states, and interactions with the external environment, including customers, service providers, and other internal processes.
Following this, BPMN Style is discussed, covering the grammar rules that ensure process logic is clear from the diagram alone and traceable through the model hierarchy. The style section is inspired by Strunk and White’s The Elements of Style, applying timeless principles of clarity, expressiveness, and consistency to BPMN models.
Part 3: Method and Style – Level 2. This section expands the BPMN palette by introducing more complex shapes and symbols, with a primary focus on Events, particularly the “big 3”—Timer, Message, and Error. Other events within the Analytic subclass are also covered, along with branching and merging using gateways and conditional sequence flows. The Author discusses iteration through loop and multi-instance activities, as well as multi-participant pools, highlighting how some business processes require multiple interacting pools instead of a single BPMN process.
The section concludes with a review of BPMN rules—both official and style rules—and shows how to use validation to maintain model quality and make the process logic easily traceable.
Note: This book does not cover BPMN 2.0 Choreography and Conversation models, as there has been limited interest in these B2B interaction-focused additions to the BPMN standard.
BPMN Implementer’s Guide
This section shifts focus from graphical notation to XML serialization, primarily benefiting developers and tool vendors, though it is valuable for business analysts and architects as well.
Part IV: Dealing with Non-Executable BPMN. The Author explores the BPMN 2.0 metamodel and its representation in XML Schema, focusing on the proper XML serialization of process elements within the Descriptive and Analytic Process Modeling Conformance subclasses, including data flow. The connection between the graphics model and the semantic model is explained, along with the definition of multi-page hierarchical models. The section also covers referencing reusable subprocesses and tasks imported from independent BPMN files and the importance of the model’s target Namespace. Part IV introduces the BPMN-I Profile, a set of conventions aimed at enabling non-executable model interchange by limiting serialization to a single method where BPMN 2.0 allows multiple.
Part V: Executable BPMN. This section presents the definition, referencing, and mapping of execution-related information, particularly process data, within executable BPMN models. The Author discusses BPMN concepts of services, messages, and events in an execution-related context and explains how performer assignment is modeled in human tasks.
The book concludes by showcasing executable BPMN in practice, as implemented by the first wave of BPMN 2.0-compliant BPM Suites. It reviews how point-click design in BPMS tools is reflected in BPMN 2.0 XML export and provides guidance for tool developers on aligning executable design with BPMN Method and Style, suggesting out-of-the-box solutions.