What is the main difference between PMI & Agile methodology?

So, can we reconcile this apparent disconnect? I think, in large part, we can! I think there are three major areas where Agile supporters reject Traditional Project Management – (and, in the same breath, the PMI view and PMBOK® Guide) – where this criticism either does not apply to the PMBOK® Guide, or they have misunderstood or misrepresented the PMBOK® Guide.

• Rejection of the “Waterfall Method”
• Rejection of formal change management and configuration management
• Rejection of the traditional project manager’s role and the team members’ roles

However, I would argue Agile methodologies do define a different framework and philosophical approach for managing projects that is currently not embraced in the PMBOK® Guide. The PMBOK® Guide currently defines a very formal, prescriptive - (or “Push approach”) - for managing projects. It requires, as PMPs, we should create a very detailed project management plan at the beginning of the project with its many subsidiary plans, and define accurately the three key baselines: Scope baseline, Schedule baseline and Cost baseline. We should use Earned Value Methodology on all projects.

Both are different methodologies