The aim of this bachelor thesis is to examine how librarians experience that their work situation, as well as their patrons, have been affected by the change of a library system. The chosen theoretical framework is Scandinavian institutional theory, which is implemented on the empirical data. Data was gathered through qualitative interviews with four librarians at four different public libraries who are part of the same library consortium, which transferred to the new library system Quria during the same time. Results show that librarians experience several changes in their work due to the change of their library system. Some aspects of their work, like searching for information and handling books, has led to their work going slower than before. Other aspects, such as advertising activities, have improved. A recurring problem is the operational disturbances in the new library system. Regarding the patrons, the librarians believe that they have been affected to some extent as the work at information desks takes longer. The patrons are also believed to be affected due to the operational disturbances, as the website is linked to the library system, therefore shutting down simultaneously. This study also shows some issues seen as permanent due to the change of a library system such as the organizational framework and vocabulary, which indicate that there are limitations for libraries in their use of a library system. Overall, conclusions show that the change of a library system both enables and hinders the way libraries work.