Communicate to the key stakeholders that the project baseline could not be estimated due to the new framework being used.

Ask the project team to create a high-level budget baseline for the project and provide more detail only for the first project stages.

Review organizational process assets (OPAs) for similar projects to determine the schedule, costs, and resources required to execute them.

Refine the amount of work required for the project with the project team and perform a detailed project baseline accordingly.