One of the key stages of the development of a fault tolerant Service oriented Architecture is the creation of Diagnosers, which monitors the system’s behaviour to identify the occurrence of failure. This paper presents a Model Driven Development (MDD) approach to the automated creation of the Diagnosing Services and integrating them into the system. The outline of the method is as follows. BPEL models of the services are transformed to Deterministic Automaton with Unobservable Event representations using MDD transformations. Then, relying on Discrete Event System techniques a Diagnoser Automaton for the Deterministic Automata are created automatically. Finally, the Diagnoser Automaton is transformed into a new BPEL representation, which is integrated into the original architecture.