Miyata's theorem states that:
For a commutative Noetherian ring R, and a short exact sequence:
$0 \rightarrow M \rightarrow P \rightarrow N \rightarrow 0$
if $P$ is isomorphic to a direct sum of $M$ and $N$, then the sequence split.
Is there a similar criterion for sheaves of $O_X$-modules on a variety? Thanks.