This paper describes our research into the application of fault injection to Simple Object Access Protocol (SOAP) based Service Oriented-Architectures (SOA). We show that our previously devised WS-FIT method, when combined with parameter perturbation, gives comparable performance to Code Insertion techniques with the benefit that it is less invasive. Finally we demonstrate that this technique can be used to compliment certification testing of a production system by strategic instrumentation of selected servers in a system.