PhD Defence Robson Medeiros

Cost Management of Service compostion 

Robson Medeiros is a Double degree PhD Student in the Services, Cybersecurity and Safety researchgroup. His supervisor at the University of Twente is Professor Roel Wieringa from the Faculty of Electrical Engineering, Mathematics and Computer Science (EEMCS). His supervisor at the Federal University of Pernambuco is professor Nelson Souta Rosa.  

Many organisations across the world have adopted Service-Oriented Architecture (SOA) to interconnect their computing infrastructures (Business-to-Business) and offer interfaces to their customers (Business-to-Customer). SOA can help these organisations access the market more quickly, respond to changes in a business environment, improve business processes and customers’ services and even reduce costs. In SOA, service composition has emerged as an important strategy to enable collaboration of applications provided by different organisations (Business-to-Business). With the increasing number of Web services having similar functionality but different pricing schemes, choosing the most appropriate set of services with the lowest cost has been a challenge in service compositions. In our exploratory literature review to identify the challenges and current concepts related to the treatment of the cost of service compositions, we observed the existence of several approaches to manage costs in Service-Oriented Computing (SOC). However, most of these approaches cannot cope with complex cost behaviours. Moreover, we did not find any solution that treats cost throughout the service composition life-cycle. Thus, the main objective of this thesis has been to develop a framework to manage cost throughout the service composition life-cycle in an integrated way, taking into account all classes of cost behaviour and all types of cost drivers. To achieve this objective, we first provided a metamodel to express cost behaviours of computational services by taking into account some characteristics of SOA and service cost, such as that services can have a particular cost for each operation and that service costs can have several types of cost drivers. In addition, we developed algorithms to analyse the cost of service compositions and atomic services. Additionally, we proposed an architecture for developing software environment that are able to manage the cost throughout the service composition life-cycle. Finally, we implemented a prototype based on the proposed architecture and performed simulations that show the effectiveness and efficiency of our approach to manage the cost of service composition.