The aim of this study is to clarify the change over time in the elements of work (job elements) and their features, as well as the relationship between job elements and the type of job, job class, and the role of the hospital they are performed in. A time-motion study was conducted on the medical staff in the surgical wards of two hospitals. An analysis of roles bys by (a) type or class of job type, and (b) hospital function was conducted. The number of working hours was analyzed, as well as the ratio of working hours with respect to direct and indirect job elements. The job elements required for each medical staff member were proven to differ by type of job (doctors and nurses) and also by job class (nurse leaders and staff). When comparing between hospital the differences in job elements were proven not to be a result of differences in hospital function, but to result from the ward system (ward design and nursing system).