Confusing isn't it?
It should not be - once we truly and correctly understand the PMBOK® Guide ... What is important to recognize is that to effectively manage a project:
- You need a methodology that can be developed internally, or you can use something like SUKAD's CAM2P project management methodology,
- You need the processes, such as the PMBOK® Guide offers, and
- You need project management competence ... such as is advocated by IPMA.
We suggest that the above three points are the core elements of project management maturity.
Our recommendation is that you read, read and read again, and compare what we have presented with what you currently practice. Then make some adjustments, at least on a trial basis, and see if that makes a difference to your project outcomes. There might be the normal learning curve but we know organizations are capable of judging whether what we propose adds value or not.