  Flavor $SU(3)$ symmetry is a powerful tool to analyze charmed baryon decays.
In this work, we propose an approach to generate $SU(3)$ sum rules for the
singly and doubly charmed baryon decays without writing the Wigner-Eckhart
invariants explicitly. The $SU(3)$ sum rules are computed routinely in several
master formulas. Hundreds of $SU(3)$ sum rules are found to serve as test of
the flavor symmetry in the charmed baryon decays.
