doubts about RMA order, integrations & parts purchase in Depot repair process flow

Summary:

We are trying to implement the entire depot repair process flow in Oracle fusion but have some doubts.

Content (required):

The standard depot repair process flow given by oracle is as follows:

We had some doubts in this process flow:

1.Against which sales order is the RMA for damaged product being created? is it created against the original sales order used to ship the product to the customer?

2.Are there any native integrations between oracle engagement cloud and SCM modules(order management, inventory and service logistics) or new integrations need to developed for implementing this flow? Also does service logistics have a native integration with maintenance cloud?