One of the main purposes of the power quality monitoring systems (PQMS) in Europe is providing system-wide compliance and benchmarking reporting capabilities. A common structure of the PQMS includes power quality monitors and other intelligent electronic devices (IED) from different manufacturers. Creating reports using data from such a heterogeneous system is usually a very complex task, since different manufacturer software usually offer no interoperability options, and the data structure is often not uniform. To avoid time-consuming and error-prone manual report generation, flexible and extendible data management and reporting systems were developed, offering automatic integration of data from different makes and types of PQ monitors, and from existing databases. This system provides friendly and comprehensive user-interface, allowing easy configuration and customization of complex data management, integration, analysis, and reporting features.