Function modeling is high-level abstraction of behaviors of artifacts observed by users. While theoretically function modeling may not be a completed area and still many developments can be expected, practically this is a theory, tool, and technique that engineers think completely useless. However, the complexity of modern product development processes is extremely high and its complexity reduction and management are urgent tasks. To do so, function modeling is considered a critical tool. In this talk, I would like to discuss potential use of function modeling and directions of its future development.