The ROSECON System - a Computer Tool for Modelling and Analysing of Processes. The paper provides a general description of the ROSECON system - a software tool for automated discovering net models from data tables as well as predicting model changes in time. Especially, we concentrate one’s attention on abilities of ROSECON for modelling and analysing of processes. Many of the ROSECON methods and algorithms have originated from the rough set theory introduced by Z. Pawlak in 1982 as well as the Petri net theory proposed by C.A. Petri in 1962