I agree with SIDNEY. Certification bodies, like AFAQ France, urges CA and PA procedures should be prepared separately because of the following reasons:
1. In old ISO standard 1994 eddition these procedures were combined but in new version of ISO CA and PA are defined under a separate heading both requiring a procedure.
2. After corrective actions , preventive action were ususally neglected.
3. In defining both CA and PA in a single procedure PA requirements were ususally ignored
4. People usually considered CA and PA are to be followed together ignoring the fact that PAs alone can be raised at any time by any one.
To my understanding, you can combine both procedures but the action procedures must be defined separately, under different headings.