De or het successieplanning?

The correct Dutch article is:

de successieplanning

Rule Words ending in -ing: almost always de. See the rule

How to use successieplanning

the successieplanningde successieplanning
this successieplanningdeze successieplanning
that successieplanningdie successieplanning
our successieplanningonze successieplanning
your successieplanningjouw successieplanning
every successieplanningelke successieplanning
which successieplanning?welke successieplanning?
a big successieplanning / the big successieplanningeen grote successieplanning, de grote successieplanning