Change Management of Long Term Composed Services

We propose a framework for managing changes in Long term Composed Services (LCSs). The key components of the proposed framework include a Web Service Change Management Language (SCML), change enactment, and change optimization. The SCML is a formal language to specify top-down changes. It is built upon a formal model which consists of a Web service ontology and a LCS schema. The Web service ontology gives a semantic description on the important features of a service, including functionality, quality, and context. The LCS schema gives a high-level overview of a LCS's key features. A top-down change is specified as the modification of a LCS schema in the first place. Change enactment is the process of reacting to a top-down change. It consists of two subcomponents, including change reaction and change verification. The change reaction component implements the proposed change operators by modifying a LCS schema and the membership of Web services. The change verification component ensures that the correctness of a LCS is maintained during the process of change reaction. We propose a set of algorithms for the processes of change reaction and verification. The change optimization component selects the Web services that participate in a LCS to ensure that the change has been reacted to in the best way. We propose a two-phase optimization process to select services using both service reputation and service quality. We present a change management system that implements the proposed approaches. We also conduct a set of simulations to assess the performance. Acknowledgments First and foremost, I would like to thank my advisor, Dr. Athman Bouguettaya, for his continuous support during my entire PhD study. Dr. Bouguettaya's keen interest and passion in research, his vision in the fields of service computing and data management, and his disciplined research methodology truly inspired me and will guide me throughout my career. It is the tremendous time and effort that he devoted on advising that trained me into a real researcher. His disciplined guidance is the most valuable asset for me to learn how to conduct independent and creative research. Dr. Bouguettaya's dedication, patience, and inspiration are a great fortune to my PhD study and are highly appreciated.