A system and appertaining method isolates a hardware or user error in a software controlled apparatus e.g., an NMR-apparatus. A diagnostic function is added to an event log that uses a causality model to analyze the event log. A series of events in the event log is evaluated by comparing the events with at least one of a number of root cause related patterns, and a best match of these patterns is used to assign a root cause for the error. Various repair actions may be associated based on a probabilistic model. Additional information may be utilized to modify or improve respective probabilities associated with causes and/or repair actions. This additional information may utilize other automated diagnostic information or may query users for additional information.