International Journal of Cooperative Information Systems

XML has too many low-level details that hinder high-level conceptual design. We therefore propose DTD graphs and XSD graphs as a mean for conceptual modeling of XML applications. Similar to document type definitions (DTDs) and XML schema definitions (XSDs), DTD graphs and XSD graphs are trees, and as such they can easily be mapped to DTDs and XSDs for implementation. Unlike DTDs and XSDs, DTD graphs and XSD graphs capture various high-level data semantics such as cardinality, ISA, participation, aggregation, categorization, and n-ary relationship. Furthermore, this paper also presents transformation rules between DTDs and a large class of XML Schemas and an algorithm that inputs users’ requirements and outputs a DTD graph that has a minimum number of redundancy-free fragments. As a result of these good properties, the resulting DTD or XSD facilitates query processing and update.

In a world of wide-scale information sharing, data are described in different formats, i.e. data structures, values and schemas. Querying such sources entails techniques that can bridge the data formats. Some existing techniques deal with schema mapping and view complementary aspects of the problem. Important ones, consider producing all the possible mappings for a pair of schemas, insinuating accompanying semantics in the mappings and adapting correct mappings as schemas evolve. In this work, we consider the problem of discovering mappings as schemas of autonomous sources are gradually revealed. Using as an example setting an overlay of peer databases, we present a schema mapping solution that discovers correct mappings as peer schemas are gradually revealed to remote peers. Mapping discovery is schema-centric and incorporates new semantics as they are unveiled. Mapping experience is reused and possible mappings are ranked so that the best choice is presented to the user. The experimental study confirms the suitability of the proposed solution to dynamic settings of heterogeneous sources.

Workflow management systems (WfMSs) also known as business process management systems (BPMSs) are increasingly popular in today’s large organizations. In spite of this popularity, many processes are still supported by ad hoc systems based, for example, on spreadsheets and homegrown databases. In particular, there is a lack of flexible process automation approaches that are able to bridge the gap between these ad hoc solutions and large-scale systems. This paper reports on a flexible WfMS and approach that blends formal and informal workflow modeling and execution, thus supporting different types of processes. We validate our work by discussing its design and implementation, and by analyzing its use in four different use cases within Siemens business units. We also discuss the role of action items as important flexibility mechanisms behind our model. Showing its ability to handle exceptions and ad hoc workflows.