Cloud computing services are already widespread in the business world, while the use of these services in the public sector is smaller and their introduction slower . Constantly shrinking budgets for information and communication technology (ICT), with the citizens' demands for quality e-services, forces the public sector around the world to the rationalization and consolidation of resources, infrastructure and ways of providing their services [1, 8]. One of the possible answers to these challenges lies in the use of cloud computing services. Some countries have already recognized the opportunities and challenges of such services, and wrote down the use of them in the national ICT strategy and have already started with their introduction [10, 11], including the Republic of Slovenia .
The Government of the Republic of Slovenia has taken steps at the level of the state administration on the basis of the situation analysis and strategic documents [28, 31, 33, 34], which led in the year 2015 to the reorganization of the state informatics and to the establishment of the National cloud computing (DRO). Establishment also based on the experience of the pilot project of deploying the DRO in cooperation with the Faculty of Computer and Information Science (FRI) and the Ministry of Public Administration (MJU) [40, 41].
This master thesis presents the concept of cloud computing, the possible deployment and service models that would be suitable for our public administration. Comparison is also given with the selected deployment model of DRO, which is in a production phase from the end of 2015.
The thesis gives a proposal of a unified migration strategy for transition of applications and services in the DRO for the entire state administration. The strategy follows the examples of good practice of the deployment of cloud computing services and the consolidation of IT in state institutions abroad. The experience of the pilot project of deploying the DRO is also considered. The migration strategy includes a detailed transition plan to migrate applications and services, which also includes a proposal of rules for determining the best service model for a particular application or service. The strategy includes guidelines for management of enterprise architecture (EA)  to capture the current and destination status. Proposal for a migration strategy is supported by a case study of the application of a migration strategy for applications and services of information system of Metrology Institute of the Republic of Slovenia (MIRS), which includes a detailed transition plan and suggested most appropriate service models for individual applications and services.