This diploma thesis analyses Ulrich's concept of the multiple-roles model and the implementation of the HR Operating Model through selected theoretical bases, published qualitative and quantitative researches conducted especially in the environment of European organizations of the secondary and tertiary sector of the market. HR Operating Model is also analysed through own qualitative research conducted in the personnel department of a selected organization operating in the field of fast moving consumer goods, which becomes a part of a multinational organization. Part of the qualitative research is a descriptive case study that monitors the transformation of the organizational structure of the personnel department, the revision and the implementation of the personnel processes, the degree of its' adaptation to the specific local conditions, the descriptive case study also identifies the positive and the negative consequences of the transformation in the local personnel department. Keywords HR Operating Model, Three-legged Model, multiple-role model, HR Business Partner, transformation of the personnel department