Present invention relates to system and method for specifying and implementing IT systems, in particular for searching functionalities. Proposed is a method of specifying and system for implementing interactive systems used for data storing and analysis as well as supporting collaboration and human-computer interaction, which is based on a control flow network structure. The method and system include support for whole lifecycle of implemented systems along with their evolution in time. In particular system comprising directed control net comprising data containers and functionality codes search module for searching functionalities within directed control net by identifying input, and matching identified input with functionality code according to the directed control net structure for generating a group of identified functionalities.