Appraisal and Analysis of Various Self-Adaptive Web Service Composition Approaches

Abstract

Service-Oriented Requirements Engineering (SORE ) plays a significant role in eliciting, specifying, and validating service requirements that will be developed by Web service technology . With the increasing complexity of users’ requirements, Web services need to be combined together to fulfill them. The process of building new value-added services by integrating sets of existing Web services to satisfy users’ requirements is called Web Service Composition (WSC). The main objective of WSC is to develop composite services to satisfy users’ requirements, which does not only include Functional Requirements (FR), but also Non-Functional Requirements (NFR). One of the main challenges of WSC is how it deals with dynamic environments. Since the Web service properties and composition requirements are frequently changeable, this demands that SORE activities must be equipped with a self-adaptation mechanism to provide the most appropriate composite services and satisfy users’ requirements emerged. Self-adaptation occurs in either a proactive or reactive manner. In this chapter, we appraise and analyze existing reactive adaptation research that deals with the problem of WSC in a dynamic environment in order to identify the research gaps in this field. These approaches are classified into three categories: used of variability models, context-awareness, and multi-agent approaches. Most of these approaches are not able to deal with continuous and unanticipated changes in complex uncertain contexts because they need to define the contexts in design time. It is usually difficult to predict all of the possible situations that might arise in an uncertain environment.