We are planning for Windchill Upgrade from WC10.2 to WC12. We have customization on custom Wizard.

If its a wizard, it will not impact the upgrade process at all. You can fold in your customizations at any point you like. Remember that you will likely be doing a double hop upgrade. I recommend going to 13 not stopping at 12.  The target system is just a straight up install. The upgrade process mainly impacts the database and some configuration. 

Hi @VM_10064149 

The customization transfer is not so complicated. you have to just know how the customization has been written.

usually you transfer following type of files and configuration>

class files

jsp files

mvc definition

xconf definition

service definition

customAction definition

customModelDefinition

I would say, that if you use Apache logging you have to update your code to include new apache logging package.

org.apache.logging.log4j

also there are some API changes that you have to confirm that all your customization could work. 

PettrH

Hi @VM_10064149,

I wanted to see if you got the help you needed.

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Thanks,
Anurag