05 Fakultät Informatik, Elektrotechnik und Informationstechnik
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6
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Item Open Access Abstract syntax of WS-BPEL 2.0(2008) Kopp, Oliver; Mietzner, Ralph; Leymann, FrankWS-BPEL 2.0 is the current version of the "Business Process Execution Language for Web Services". Until now, no formal definition of its syntax exists. We present a complete syntax of WS-BPEL 2.0 of both abstract and executable processes.Item Open Access Coordination protocols for split BPEL loops and scopes(2007) Khalaf, Rania; Leymann, FrankThe document presents an approach to enable loops and fault handling, compensating scopes to be split among a set of BPEL processes running on different BPEL engines. A mechanism to split a scope or loop into multiple fragments is presented, then a protocol is defined that can be used to coordinate fragments of a loop or a scope so that those fragments run as if they had been in a single process. The requirements for running split scopes and loops are explained. For compensation, this paper focuses on explicit compensation and makes the assumption that compensation handing does not fail. Two protocols are defined such that they may be plugged into the WS-Coordination framework. The messages between the participant fragments and the coordinator are defined. The information about the participating processes that the coordinator needs to have is specified. An algorithm is provided to locate a fault handler in the hierarchy of scopes that can handle a particular BPEL fault. Additionally, the behavior of both participants and the coordinator are specified.Item Open Access Propagation of states from BPEL process instances to Chevron models(2011) Schumm, David; Karastoyanova, Dimka; Leymann, Frank; Lie, SumadiThis report describes key aspects of a code library that we developed for the purpose of state propagation for business process monitoring on different levels of abstraction. The library supports the propagation of execution states of process instances based on the Business Process Execution Language (BPEL) to process models specified in the "Chevron" language. The Chevron language is an abstract, non-executable process language that we especially designed for abstract process instance monitoring purposes. The look and feel of this graphical language is similar to value chains. The basic concept of the Chevron language is based on Chevron-shaped charts which can be modeled in Microsoft PowerPoint to describe a process on a high level of abstraction. We aim at enabling the use of high-level process in order to monitor the instance status of a much more detailed, lower-level model. We describe the overall procedure of performing state projections along a concrete scenario. We describe a format for state propagation rules which define how the status of activities of a BPEL process instance should be projected to the elements of a Chevron model. We present a format to serialize process models in the Chevron language. We present a graphical template based on Scalable Vector Graphics (SVG) which we employ to render a stateful Chevron model graphically. The Chevron language is just one language to be used for abstract representation of process instances. However, the approach for state propagation is generic and can be applied for other languages, too.Item Open Access WS-BPEL extension for semantic web services (BPEL4SWS), version 1.0(2008) Karastoyanova, Dimka; Van Lessen, Tammo; Leymann, Frank; Nitzsche, Joerg; Wutke, DanielThe Web Services Business Process Execution Language, version 2.0 (WS-BPEL 2.0 or BPEL for brevity) introduces a model for business processes based on Web services. A BPEL process orchestrates interactions among different Web services. The language encompasses features needed to describe complex control flows, including error handling and compensation behavior. BPEL for Semantic Web Services (BPEL4SWS) uses Semantic Web Service Frameworks to define a communication channel between two partner services instead of using the partner link which is based on WSDL 1.1. It enables describing activity implementations in a much more flexible manner based on ontological descriptions of service requesters and providers.Item Open Access A prototype for view-based monitoring of BPEL processes(2011) Schumm, David; Latuske, Gregor; Leymann, FrankThis report describes the initial version of a tool for business process monitoring based on process viewing techniques. The tool, Business Process Illustrator (BPI), has been developed in the course of a Diploma Thesis which has been conducted at the Institute of Architecture of Application Systems. BPI is a Web-based tool for monitoring the execution of business processes. It displays the current state of a process instance in form of a process graph which is refreshed regularly. The initial version of the prototype supports regular process monitoring of processes based on the Business Process Execution Language (BPEL), plus process view transformations to reduce complexity and to ease analysis of process instances.Item Open Access An event model for WS-BPEL 2.0(2011) Kopp, Oliver; Henke, Sebastian; Karastoyanova, Dimka; Khalaf, Rania; Leymann, Frank; Sonntag, Mirko; Steinmetz, Thomas; Unger, Tobias; Wetzstein, BranimirThis report presents an engine-independent WS-BPEL 2.0 event model. It supports both passive monitoring and active control of process execution by external applications. Some of the assumptions in the presented event model are inspired by a particular implementation, e.g. fault handling and compensation; however they are kept as general as possible, so that they can be mapped on other engine-specific approaches to tackle faults and support compensation. In addition, the report draws on the experience of some of the authors in business process management and software development. The overall BPEL event model consists of a set of event models for the different types of BPEL entities that change their states: processes, process instances, general activities, scope activities, invoke activities, loops, links, variables, partner links, and correlation sets. The event model is used by the authors of the report in several projects, all utilizing process life cycle events in different scenarios.Item Open Access Note on syntactic details of split BPEL-D business processes(2007) Khalaf, RaniaThe document presents the syntactic details of the generation of process fragments created by the algorithm in [1], which defined the mechanisms for splitting a business process defined using a variant of WS-BPEL. The variant, BPEL-D, replaced BPEL’s variable style of data handling with explicit data links. We add new support in this note for syntactically splitting loops and scopes.Item Open Access WS-BPEL extension for compliance fragments (BPEL4CFrags), Version 1.0(2011) Görlach, Katharina; Kopp, Oliver; Leymann, Frank; Schumm, David; Strauch, SteveThe Web Services Business Process Execution Language, version 2.0 (WS-BPEL 2.0 or BPEL for brevity) introduces a model for business processes based on Web services. A BPEL process orchestrates interactions among different Web services. The language comprises features required to describe complex control flows, including error handling and compensation behaviour. BPEL for Compliance Fragments (BPEL4CFrags) enables the specification of compliance fragments providing a reusable solution for implementing and meeting compliance requirements. The compliance fragments are not necessarily executable. Providing process modeling support at design time requires the completion of not directly executable compliance fragments, because compliance fragments contain several degrees of freedom, into already existing executable BPEL processes. Moreover, assistance for creation of executable BPEL processes from scratch during IT refinement has to be provided.Item Open Access Using variability descriptors to describe customizable SaaS application templates(2008) Mietzner, RalphCustomizable applications play an important role in software as a service (SaaS) scenarios. SaaS application providers want to exploit economies of scale by offering the same basic application to many customers. As customers have different requirements for the same type of application, SaaS vendors must offer so-called application templates that can be customized by their customers to be tailored exactly to their needs. Therefore variability points (i.e., points in an application template that can be customized) need to be made explicit and constraints for these variability points need to be specified. We introduce variability descriptors as a means to describe variability points for SaaS application templates independent of the artifacts (such as GUI components, workflows, configuration files, etc.) that make up the application.Item Open Access Realizing enterprise integration patterns in WebSphere(2005) Scheibler, Thorsten; Leymann, FrankOver the last few years, patterns became focus of many activities in both, software development and research. Because of the financial significance of enterprise application integration (EAI) technologies corresponding patterns in this area are especially important and, thus, found a lot of interest. Even a standard textbook has been well-established in this space ("Enterprise Integration Patterns"). People are asking for guidelines about how to use the patterns from this textbook in their environment. A Whitepaper of Hohpe provides a sample integration scenario together with guidelines of how to implement this integration scenario based on a subset of the patterns in the BizTalk Server 2004 environment. In this document, we use the same scenario and the same patterns as in this Whitepapper and show how to implement them in WebSphere.