To extend the Pega Foundation for Healthcare (PFH) data model:

Direct Inheritance for Extension (B):

Use direct inheritance to extend the foundation data model provided by PFH. This ensures that the core data model remains intact while allowing for the addition of new fields and data classes specific to the company's needs.

Pattern Inheritance for Behavior (B):

Utilize pattern inheritance to extend application-specific behavior. This allows for customization and the addition of application-specific logic while maintaining a clear separation from the core data model.

References:

Pega Foundation for Healthcare Implementation Guide

Pega Inheritance Models Documentation