Günter Preuner

Integration of Web services into workflows through a multi-level schema architecture

Many organizations provide access to their workflows via Web interfaces, giving customers the opportunity to create and manipulate business cases interactively according to a predefined set of operations. Since enterprises can request such Web services in order to satisfy their business goals, it may be desirable for these enterprises to access Web services not only interactively, but to import and integrate them into their own workflow management systems and to invoke them from within workflow applications. There are several initiatives to standardize the specification of services in order to provide them to enterprises for import. Yet currently most providers of Web services do not support these specifications. Thus, requesting enterprises must extract the workflows and business objects behind the provided Web interface from the visible Web pages. This paper presents a design architecture for extracting the Web interface and the underlying workflows and business objects from a Web site in consecutive extraction phases, each phase resulting in a conceptual schema at one particular level in the architecture. The architecture satisfies service independence, i.e., changes in the Web interface do not require a complete redesign of the conceptual schemas, and level-specific integration, i.e., extracted Web services can be integrated at different design levels depending on the purpose of integration.

Translating XQuery into XSLT

The WWW Consortium (W3C) has recently presented a working draft of XQuery, which is intended to serve as standardized query language for XML. XQuery and other high-level query languages for XML documents are not yet implemented by commercial products. Yet many browsers have already built-in XSLT support for transforming XML documents. XSLT is a standard way of performing structural rearrangement or presentational transformation of XML documents, but formulating complex queries is, compared to XQuery, difficult and error-prone. If XQuery expressions could be translated into XSLT (e.g. by a translator written in Java or XSLT itself), the benefits of XQuery would be immediately available to a wide range of commercial products. This paper introduces a process for translating queries formulated in XQuery syntax into XSL stylesheets. The process is described independently from a particular implementation by means of an ASM (Abstract State Machine). The ASM traverses the parse tree of a particular query and translates each node into corresponding XSLT commands. The result of this translation process is an XSL stylesheet that can be applied to an XML document in order to perform the given query. The presented ASM can be easily coded in Java or XSLT to implement a prototype XQ2XSL translator.

A three-level schema architecture for the conceptual design of web-based information systems: from web-data management to integrated web-data and web-process management

It has been recognized only recently that, like databases, web sites need models and schemes. Data-intensive web sites are best developed using a multi-level design approach proceeding from data design via navigation design to web-page design. Modern web-based information systems are no longer static in nature. Rather they are dynamic. Besides querying, they support workflow tasks and e-commerce transactions. The design of such systems needs to consider the underlying business process next to the data. Their integrated design has been mainly treated in an ad-hoc way so far. In this paper, we present a three-level schema architecture for the conceptual design of dynamic web-based information systems. We employ an object-oriented approach that integrates data and process management and complements previous approaches for the design of data-intensive web sites.

Observation Consistent Integration of Views of Object Life-Cycles

A commonly followed approach in database design is to collect user views on the database and to develop the conceptual schema of the database by integrating these views.

Behavior-Consistent Composition of Business Processes from Internal and External Services

E-business processes are typically developed by composing internal processes and external processes offered by service providers. Whereas e-service integration has received considerable interest recently, the relationship between the behavior of the composite process and the behavior of the constituting service processes has not yet been thoroughly investigated.

Static–Dynamic Integration of External Services into Generic Business Processes

Organizations usually handle their business cases by requesting external services that are integrated with internal procedures to a composite business process. External services may be atomic activities or, more often, arbitrarily complex processes.

Methoden und Modelle für den Entwurf von Data Warehouses

Data Warehouses sind Datenbanken, die Unternehmensdaten fur interaktive und automatische Datenanalysen verwalten. Der Beitrag behandelt die zentralen Phasen im Entwurf von Data Warehouses sowie die dafur verfugbaren Modelle.

View Integration of Object Life-Cycles in Object-Oriented Design

Object-oriented database schemas are often defined by several future users of the planned database, where each user defines a schema representing his/her view on the database; the complete database schema is defined by integrating these views in a subsequent step. Behavior of objects is often defined at two levels of detail: at the level of methods and at the level of object life-cycles that represent the overall behavior of objects during their life time. This paper presents an approach to integrate views of object life-cycles to a complete object life-cycle of an object type. We will particularly consider the problem that different users know about parts of the object life-cycle at different levels of detail and often do not consider exactly the same set of entities.