Analysing a communication performance of an IED

The present invention is concerned with an analysis of a communication stack performance of an Intelligent Electronic Device (IED) in a communication network of a Substation Automation (SA) system. The IED processes network messages that are transferred with, or belonging to, a specific configurable SA communication service. A plurality of application level scenario corresponding to a high communication load is executed. Among all network messages captured or intercepted during the scenario, the network messages destined to the IED and sent by the IED in response arc identified. A number of the identified messages, a number of specific communication protocol elements or data items related to a service-specific property, as well as a number of changed protocol elements, indicative of an SA event, for which the value of the data item has changed compared to the value of the same data item in a previous message, are determined. An IED-intrinsic processing time of the identified messages is likewise determined, based on which parameter values of a service specific processing time model are calculated.