Process management approaches all pursue standardization, of which evidence-based medicine (EBM) is the most common form in healthcare. While EBM addresses improvement in clinical performance, it is unclear whether EBM also enhances operational performance. Conversely, operational process standardization (OPS) does not necessarily yield better clinical performance. The authors have therefore looked at the relationship between clinical practise standardization (CPS) and OPS and the way in which they jointly affect operational performance. The paper aims to discuss this issue.