Abstract
This paper aims to present a method of creating architectures which allow monitoring occurrence of failure in Service oriented Architectures (SoA). The presented approach extends Discrete Event Systems techniques to produce a method of automated creation of Diagnoser Service which monitors interaction between the services to identify if a failure has happened and the type of failure. To do so, a formal representation of business processes is introduced, which allows modeling of Observable/Unobservable events, failure and the type of failure. The paper puts forward a set of algorithms for creating models of Diagnoser Service. Such models are then transformed into new Services implemented in BPEL, which interact with the existing services to identify if a failure has happened and the type of failure. The approach has been applied to an example of diagnosis of Right-first-time failure in Services used in telecommunications.