Human resources managementThe concept of HR function and its theoretical perspectives (meaning, content, levels, etc.). Analysis of how the HR function should be organized according to HRM theories and how the HR function is organized in practice within different organizations. Identification of changes (direct and indirect) that influence the HRM function. Discussion of the ways in which these changes impact the HRM function and how the HRM function might respond to the changes. The function can be understood by looking at which HRM activities are performed by which individuals in a company. So one way of looking at the HR function is to look at what is (to be done): the human resources management activities. The other way to look at the HR function is to look at who should do/do it. Valverde et al. (2006) combine both aspects of the HR function and explain that it does not only contain the set of activities carried out by the HR department, but is considered as all managerial actions at any level of the organization that have to do with the organization of the work and the entry, development and exit of employees. Valverde et al. (2006) identify different levels within the organization involved in the execution of HRM activities. These levels are top management, line management, the HR department and external suppliers. Valverde et al (2006) distinguish human resource management activities along the line of activities involved and identify: strategic decision making and leadership, operational decisions and daily people management, service provision, policy definition and diagnosis, monitoring and activities follow-up and high-level human resources management specialist activities. Valverde et al. (2006), based on empirical research, conclude that in different organizations different human resource management activities are performed by different combinations of the levels of the human resource function. Valverde et al. identify seven possibilities. For example, in some organizations all levels are involved in all HRM activities while in other organizations a specific HRM activity is performed by a specific level. Caldwell (2003) focuses on “what needs to be done.” He distinguishes human resource management activities by examining both the classification used by Storey (1992) and Ulrich (1998). Storey's model distinguishes four generic categories along the degree of intervention and the degree of strategic or operational focus. The four roles identified by Storey are changemakers, consultants, regulators and handmaids. Ulrich distinguishes four roles of the HR function based on the degree of focus on processes or people and the degree of strategic focus or operational focus. The four roles identified by Ulrich are the strategic partner, the change agent, the administrative expert and the employee champion.