Compatibility of Data-Centric Web Services

Before using a service in a composite framework, designers must ensure that it is compatible with the needs of the application. The inputs and outputs must comply with the intended ranges of data in the composite framework, and the service must eventually return a value. This paper addresses compatibility for modules described with document-based workflow nets, that can depict the semantics of active XML (AXML) systems, a language for Web Services design. The behavior of non-recursive AXML specifications with finite data can be represented as Docnets, i.e., finite labeled Petri nets carrying information on document types they transform. Compatibility of docnet modules is characterized in terms of a decidable reachability property in the underlying net. Finally, we show the distributivity of compatibility over composition, which allows a faster semi-decision algorithm to verify compatibility between sets of modules.