The Police in the Netherlands are composed of ten regional operating units. The human resource (HR) department makes good police work possible by onboarding and supporting all officers and staff to fulfill their daily duty. Machteld is a business operations specialist, and Marianne is a business controller at the HR shared services center. Traditionally, knowledge workers have been driving process improvements based on their personal expertise and gut feeling. However, most processes in the HR administration are now digitized. Therefore, the ambition is to move towards process improvements that are based on data. Machteld and Marianne share their experiences from three projects, where they showed facts and figures that sometimes confirmed and sometimes refuted assumptions.