Business Process Improvement (BPI) is a systematic approach to help an organization optimize its underlying processes to achieve more efficient results.  
It should be noted that BPI focuses on "doing things right" more than it does on "doing the right thing". In essence, BPI attempts to reduce variation and/or wastage in processes, so that the desired outcome can be achieved with better utilization of resources.
BPI works by:
Defining the organization's strategic goals and purposes
(Who are we, what do we do, and why do we do it?)
Determining the organization's customers (or stakeholders)
(Who do we serve?)