The main purpose of this thesis was to open the migration process during the fusion in KuntaPro Oy. KuntaPro Oy produces finance and human re-source services and help in knowledge-based management with different platforms and software to public sector.

The thesis is built in very theoretical way and focuses on services. The work includes a lot of theoretical texts enriched with data from the com-pany. The first part of the thesis contains information about Microsoft O365 as a service, Microsoft Exchange server and Microsoft Azure as platforms. The main platforms in this thesis was Microsoft O365 and Mi-crosoft Exchange.

The practical part includes the steps of the migration process during cut-over and what work goes into them. As a result of this thesis KuntaPro Oy is provided with a compact packet of information.