Should I change GUID of PatchCreation Element every time I make a new patch?

Question

I made two sequential .msp patches for an .msi package for a test purpose(In a way decribed in http://wix.sourceforge.net/manual-wix3/patch_building.htm).

First time, I gave the same GUID to PatchCreation Element of each patch and the first patch applied successfully to original product(I could see the entry for the first patch in ARP menu). But, second patch didn't apply on to the first patch at all. It never showed any error message when launched but it didn't appear in ARP menu and didn't update any file, too.

So, I changed the GUID of PatchCreation Element of second patch and recreated second patch and it applied well on to the first patch(its entry appeared in ARP menu and it updated files).

Is this right way to create each patch in the same patch family: Should I change the GUID of PatchCreation Element for every single patch?

Answer 1

Yes, it uniquely identifies a patch package, much like Package/@Id identifies an .msi package.