Purpose: The main aim is to describe and analyze the chances in work content, work development and managers' support in the integration processes at different levels.
Theory: Theoretical background consists of the integration models and the change management theories.
Methods: Three different case studies using before–after follow-up designs in Finland. These case studies include three merger cases where the data were collected by questionnaires from staff 1) the merger of social and health sector in local level (n=251–263), 2) the merger of hospital districts (n=9241–9178) and 3) the merger of home help and home care (n=68–87).
Results and conclusions: In all cases work content changed depending partly on the work tasks and functional sectors. Major changes were in work practices in social sector and in some home care areas. The workers perceived support from managers important although they had received support very little.
Discussion: These case studies describe structural integration in different contexts, however, it seems that same phenomena exit in all merger cases. Managers have an important supporting role in determining the success of merger processes.