[en] process Information System (PIS) of Nuclear Power Plant Krsko (NEK) is newly installed distributed and redundant process computer system which was built in NEK (Phase I: 1991-1995) to integrate the following main functions: - Signal Data Acquisition from the technological processes and environment - Implementation of the basic SCADA functions on the real time process signals data base - Execution of complex plant specific application programs - Advanced MMI (Man Machine Interface) features for users in MCR - Process data transfer to other than Main Control Room (MCR) locations - Process data archiving and capability to retrieve same data for future analysis PIS NEK architecture consists of three hierarchically interconnected hardware platforms: - PIS Level 1, DAS (Data Acquisition System) Level - PIS Level2, Level for MMI, application programs and process data archiving - PIS Level 3, Level for distribution of process data to remote users of PIS data. (author)