1. A method of operating an electrical machine, wherein the operation of the machine is modelled by an electromagnetic finite element analysis technique prior to operation, the analysis including an analysis based on model parameters corresponding with at least one fault condition, so that at least one effect of the fault condition is predicted, and in which operation of the machine is monitored during use, by comparison of live measurements with the results of the finite element analysis, thereby allowing the occurrence of the fault condition to be diagnosed.