The development of an information advising system is based on the formation of fuzzy models describing a reciprocal factor effect of the internal envi-ronment upon each other and the plant external environment influence upon the internal one. The offered information advising system has a subsystem for data input, a diagnostic unit, an assessment unit and knowledge base. The subsystem of data input is responsible for experts’ assessment input, interconnections and a user query formation. In the evaluation unit there are presented procedures for the effectiveness assessment of the measure complex with the consideration of environment influence upon factors of internal environment. In the unit of a diagnostic trend there are formed factor classifiers of external and internal environment, the selection of management decisions on basis of the formed recommendation set. In the unit of diagnostic trend there are saved tables of the influence of external environment factors upon internal environment factors and accounts are under formation. The system knowledge base contains experts’ assessment archive, formalized data of experts’ competence and a set of experts’ recommendations for various areas of knowledge.