Although BPMN is widely accepted as the language of choice for business process diagrams, few process modelers know how to use it correctly or effectively. This book shows you how. It explains the shapes and symbols you need to know, and which ones you can ignore. It provides a prescriptive, top-down methodology for turning a blank page into a complete process model. And it explains the elements of BPMN style, principles of composition that make your models not only correct per the BPMN 2.0 specification but easily understood without reference to attached documentation. The Method and Style approach allows BPMN models to be shared across the business, or between business and IT, revealing the process logic consistently and unambiguously from the diagram alone. The second half of the book, the BPMN Implementer's Guide, is addresed to developers and BPMN tool vendors. It explains the XML underneath the shapes and symbols, including the BPMN 2.0 metamodel and schema, the Descriptive and Analytic Process Modeling Conformance subclasses, and the BPMN-I Profile for interoperability between tools. Few tools serialize BPMN correctly, but the Implementer's Guide shows you how, both for non-executable and executable process models. The Method and Style section is completely rewritten from the first edition, incorporating feedback from hundreds of students in BPMN training. The BPMN Implementer's Guide is brand new in the Second Edition.