Surface simplification tool in CATIA

v5 release?

Yes in v5

v5 but which release?

like v5r19 or v5r21 etc. and also service pack is important.

its v5 r20

you need minimum R21 or higher service pack for R19 and R20.

ok Thank you

You got to have GSO license.

I assume you can copy&paste a simplify surface along with its (isolated) parent surface and then replace the parent to get round this.
This at least does work with rough surface and unfold.