Book Image

WS-BPEL 2.0 for SOA Composite Applications with IBM WebSphere 7

Book Image

WS-BPEL 2.0 for SOA Composite Applications with IBM WebSphere 7

Overview of this book

Business Process Execution Language (BPEL, aka WS-BPEL) has become the de facto standard for orchestrating services in SOA composite applications. BPEL reduces the gap between business requirements and applications and allows better alignment between business processes and underlying IT architecture. BPEL is for SOA what SQL is for databases. Therefore learning BPEL is essential for the successful adoption of SOA or the development of composite applications. Although BPEL looks easy at first sight, it hides a lot of potential and has many interesting advanced features that you should get familiar with in order to maximize the value of SOA.This book provides a comprehensive and detailed coverage of BPEL. It covers basic and advanced features of BPEL 2.0 and provides several real-world examples. In addition to the BPEL specification, this book provides comprehensive coverage of BPEL support on IBM's WebSphere SOA platform including security, transactions, human workflow, process monitoring, automatic generation of BPEL from process models, dynamic processes, and more.The book starts with an introduction to BPEL, its role with regard to SOA, and the process-oriented approach to SOA. The authors give short descriptions of the most important SOA platforms and BPEL servers—the run-time environments for the execution of business processes specified in BPEL—and compare BPEL to other business process languages. The book then moves on to explain core concepts such as invoking services, synchronous and asynchronous processes, partner links, the role of WSDL, variables, flows, and more.Moving ahead you will become familiar with fault handling, transaction management and compensation handling, scopes, events and event handlers, and concurrent activities and links. The authors also discuss the business process lifecycle, the correlation of messages, dynamic partner links, abstract business processes, and mapping from BPMN to BPEL.The book discusses details of using BPEL with IBM WebSphere SOA platform. You will be able to develop BPEL and SCA composite applications, and demonstrate different approaches with the help of examples in this book. You will get exhaustive information on monitoring BPEL processes, and developing dashboards.The authors explain transformation of business process models in BPMN (using Business Modeler) to BPEL and how to achieve round-tripping. The book covers a complete BPM lifecycle from modeling through implementation, execution, monitoring, and optimization, and presents advanced real-world examples. In addition to standard BPEL it also covers IBM specific extensions on the WebSphere SOA platform.
Table of Contents (16 chapters)
WS-BPEL 2.0 for SOA Composite Applications with IBM WebSphere 7
Credits
Foreword
About the Authors
About the Reviewers
Preface

Human tasks in BPEL


So far, we have seen that human interaction in business processes can get quite complex. Although the BPEL specification does not specifically cover human interactions, BPEL is appropriate for human workflows. BPEL business processes are defined as a collection of activities that invoke services. BPEL does not make a distinction between services provided by applications and other interactions, such as human interactions.

There are two main approaches to support human interactions in BPEL. The first approach is to use a human workflow service. Several vendors today have created workflow services, which leverage the rich BPEL support for asynchronous services. In this fashion, people and manual tasks become just another asynchronous service from the perspective of the orchestrating process and the BPEL processes stay 100% standard.

The other approach has been to standardize the human interactions and go beyond the service invocations. This approach resulted in the workflow...