In my opinion Process Excellence, Operational Excellence & Business Excellence are all correlated but in a hierarchy form.
Organizations to achieve the objective of meeting customer expectation, create effective business strategy, keep external stakeholders happy need to have a strong Operational Excellence. Why Operational Excellence because until and unless the organization is not culturally strong, people centric, have intellectual systems, it will not be possible to collaborate to meet the business objective and the acumen to reach Business Excellence. To an extent Operational Excellence cannot be the only driving force until & unless Process Excellence infuses standard processes there by allowing people to deliver consistently positive outcomes with minimal variations and wastes.
In-order that the right processes are created or to create a responsible but carefree culture allowing employees to collaborate and work together in achieving business goals, Personal Excellence plays a pivotal role. Until and unless we keep challenging our minds in bettering ourselves, gain knowledge, become and expert, master a trait we will not be able to move from Ape Age to what we are/ want to be. We will not be able to create standardized process or achieve Process/ Operational/ Business Excellence.