In 1998, the Royal Netherlands Army introduced a new examination system (abbreviated as BMEKL), which was based on the "workload-capability" model, to replace the old system (abbreviated as PULHEEMS), which focused on diagnosis and was based solely on the detection of diseases and infirmities. To discern differences under operational conditions between soldiers examined with one of the two medical examination systems, we performed a prospective cohort study. In the study, soldiers who had been declared fit for duty with one of the two medical assessment systems (randomized) and sent on a mission were monitored for 2 years. We used the two operational measures of availability and health care costs. In addition, the candidates were given a questionnaire twice per year during the study period. The study revealed that the soldiers assessed using the function-based BMEKL system displayed greater fitness for duty than did those assessed using the diagnosis-based PULHEEMS system. The BMEKL assessment system is a better predictor of the ability to function as a soldier in general, and with regard to deployment, health, and the locomotor apparatus specifically, than is the PULHEEMS system. Copyright © by Association of Military Surgeons of U.S., 2005.