According to the PMBOK Guide, the project manager should consider the project delivery approach (predictive, agile, or hybrid) based on the project characteristics, such as complexity, uncertainty, stability, and adaptability. The project manager should also evaluate the impact of any changes to the project delivery approach on the project scope, schedule, cost, quality, risk, and stakeholder satisfaction. Therefore, the project manager should analyze the requirements that will need to be addressed under the agile approach and determine the feasibility, benefits, and drawbacks of switching from the predictive approach. This will help the project manager to make an informed decision and communicate it to the relevant stakeholders. References:
PMBOK Guide, 6th edition, pages 19-20, 141-142.