The way in which the manager carries out his activities determines that public institutions are effective or ineffective. Inefficiency or inefficiency occurs when the manager fails to properly coordinate efficiency or effectiveness factors. In order to be effective and efficient, managers of public institutions must carry out other types of activities than those provided by traditional management functions, such as communication activities, human resources management activities, networking activities. In the paper we aim to quantify the impact of these categories of activities on the efficiency and effectiveness of public institutions. The investigation carried out within three public institutions reveals the importance of communication and human resources management activities in the perception of the responding managers.