After converting your forms files into XML files, sign into your APEX workspace and be sure you're using the schema that contains all database objects needed in the forms. Now, create a Migration Project and upload the XML files, following these steps:
Now let's review each component in the upload forms to determine proper regions to use in the APEX Application. Also, let's review the Triggers and Program Units in order to identify the business logic in your Forms Application and determine if it will need to be replicated or not.
In the following image, there are some Order's Triggers at S_ORD block level. On the left side is an image from the APEX Migration Project and an image from the Forms Builder on the right.
Please note using the Migration Project allows you to track every component object, which can be defined if the object is complete. While you're building your APEX Application you can view the Migration Project, filter only by applicable objects and review which objects are incomplete. This is a simple and clear overview of the objects, which will ensure business rules are not missed.
According to the functionality of the forms, the options to modernize them would be: