Web Services Composition Framework with Petri Net Based Schemas

The paper describes a framework for composite web service based applications, built around domain-specific composition schemas for Petri net based models of service workflows. Those schemas, implemented as a hierarchy of generic and category-specific XSD descriptions, support both user oriented functionality and automatic composing of web services by means of core web technologies. Standard syntactic and semantic descriptions of component web services are referenced by descriptive resources native to the presented framework: XSD schemas, XSLT mappings, XML definitions and automatically generated RDF metadata. Main goals of the proposed solution are: to provide flexible model for composing families of similarly structured domain-specific web service based applications, while exploiting possibilities of automation related to semantic web services, and separating users from advanced formalisms of service ontologies.