snap fit design

What type snap joint? Cantilever? Annular?? Torsion???

Are the two components of similar stiffness?
What material(s)?
What operating temperatures will the components be subjected to?
Frequent separation or a one time assembly?
x
y
z
...

There are lots of variables to consider. I'd consider starting with a design primer on snap joint design.

Snap fit calculator:
https://www.smlease.com/entries/plastic-design/how-to-design-snap-fit-joints-in-plastic-parts/

Here are some resources that may help.