Automatic Dynamic Web Service Composition: A Survey and Problem Formalization

The aim of Web service composition is to arrange multiple services into workflows supplying complex user needs. Due to the huge amount of Web services and the need to supply dynamically varying user goals, it is necessary to perform the composition automatically. The objective of this article is to overview the issues of automatic dynamic Web service composition. We discuss the issues related to the semantics of services, which is important for automatic Web service composition. We propose a problem formalization contributing to the formal definition of the pre-/post-conditions, with possible value restrictions, and their relation to the semantics of services. We also provide an overview of several existing approaches dealing with the problem of Web service composition and discuss the current achievements in the field and depict some open research areas

Enhancing Semantic Web Services Composition with User Interaction

The semantic web services composition process arranges several web services into one composite to realize complex workflows. To do this, semantic metadata of web services’ description are used. The current approaches based mainly on AI planning are immature to be used in practice. In this paper we propose an approach involving users in the semantic web services composition to help overcome problems occurring in the composition process. The basic idea is to find the users helpful in situations when preconditions are not satisfied or some input data are not available which are in demand to create a composition.

Qos aware semantic web service composition approach considering pre/postconditions

Web service composition is a topic bringing several issues to be resolved. Our work deals with the effectiveness and scalability of service composition. During composition we consider QoS and pre-/post-conditions of single services to create a composite service satisfying the user needs the best. Regarding pre-/post-conditions we propose an approach to fast determination of which services produce results expected by the user, i.e. the post-condition of which services implicates the desired condition defined in the user goal. This paper presents also a renewed version of our approach to QoS aware service composition. We achieved a dramatic improvement in terms of composition time by performing a useful restriction on the service space.