Aggregation and optimisation of trustworthiness of composite services

The chapter presents the Aniketos approach to aggregating and predicting the trustworthiness of services that are assembled from component services. Some of the important characteristics of service environments are that they are dynamic, distributed and loosely coupled. These characteristics result in the existence of different levels of functional and non-functional attributes of the services operating in such environments. Consequently, it creates challenges for interacting service consumers that require to only deal with services that are trustworthy. In service compositions, the component services may be mandatory or optional and vary in their contribution to the trustworthiness of the composite service. Composition techniques must be able to select trustworthy components and to dynamically adapt to subsequent changes in the services and the environment. The availability of multiple services providing the same or similar functionality but with different trustworthiness levels helps composite service providers to establish and maintain trustworthy compositions.