Functional harmonic analysis is an important task in music composition, accompaniment, arrangement and others. However, the solutions are still not satisfactory. The proposed process is divided into two levels: the former extends one of previous works in the domain to carry out a richer analysis of chord grids and is where the very analysis is performed, and the latter is devoted to correct some conceptual inconsistencies concerning enharmonic spelling of chords. Both levels use an engine to make inferences on some rule bases, which can be easily improved by addition of new rules. Keywords: functional harmonic analysis, roman numeral harmonic analysis.