We are a team of researchers in the Design Intelligence Laboratory of the Georgia Institute of Technology where we have been working on functional modeling for over twenty years. We have developed the Structure-Behavior-Function (SBF) language, which has been used for modeling technical systems, such as mechanical devices (Goel, Rugaber & Vattam 2009). Over the past few years, we have also used SBF for modeling biological systems and explored how constructing functional models can help students obtain a deeper understanding of such systems. Currently, we are extending our approach and language to deal with the complexities of biologically inspired design, ecological forecasting and cancer pathways. For the purposes of this workshop, we ask what are the essential aspects of function and functional modeling upon which benchmarks should be founded?