Social software supports various actors in producing user-generated content, developing and maintaining social relationships as well as establishing computer-mediated interaction and collaboration. These capabilities of social software provide manifold possibilities for a more effective and flexible design of business processes. At the same time new process management approaches allow a tighter integration of data in process execution, which leads to less rigid and less prescriptive process definitions. Main goal of this PhD project is the development of a new modeling paradigm that empowers end-users to collectively design and adapt workflows in a bottom-up fashion. The proposed solution integrates data in the process execution and is based upon adaptive models that are open for continuous improvements from end-users in order to take advantage of the collective intelligence of domain experts in an organization. In this paper we present the research agenda for our long-term goal of bridging the gap between social software and business process management.