Methods of storing data records produced from monitoring interactions between external agents and a system are described. The method defines specific interactions that occur between the external agents and the system as events of interest. A chain of interactions occurring during respective interaction sessions between a respective external agent and the system are monitored and events of interest occurring in the chain are determined. Data records from the monitored chain are produced, the respective data record including data identifying determined events of interest and data associated therewith. A profile identity, representative of the external agent, is assigned to each data record produced during an interaction session. Data records of individual events of interest are stored in a way ordered according to the type of event of interest and data records of events of interest occurring during an interaction session are stored in a way ordered according to assigned profile identity.