Providing of insight into an approach to creation of information human-operator decision support systems (IHODSS) for complex process plants as exemplified by nuclear power unit control. IHODSS functional basis is determined by accomplishing the following tasks essentially forming a triune task: prediction of power unit parameters behavior and process progress aspects, in-mode diagnostics, and early in-process recognition of anomalies; generation of recommendations on optimal process conditions. An overview of basic principles of development and function of IHODSS, software and hardware selection, as well as characterization of software and hardware suite for IHODSS tasks refinement are presented..