After the CL has been defined and the Components assigned to the CL, then the first step of an RBI analysis is to assign DMs to the Component, since the RBI analysis takes place on Component level, per Degradation Mechanism.
Assigning DMs from CLs
Typically DMs will be assigned to the Components when the RBI Analysis is started from the Component. However, it is also possible to assign DMs from the CL Details Page in the Component/RBI section:

Assigning DMs from Components
To start a new RBI Analysis for a Component and assign DMs:
- Open the Component Details page (see IMS Details Page).
- Scroll down to the RBI Analyses section.
- Click New Analysis. Note: Only the DMs identified in the Component’s associated CL will be available to be assigned.

For more information see Step 3 Start RBI Analysis and Assign DMs to the Component.