  With the rise of data-centric process management paradigms, interdependent
processes, such as artifacts or object lifecycles, form a business process
through their interactions. Coordination processes may be used to coordinate
these interactions, guiding the overall business process towards a meaningful
goal. A coordination process model specifies coordination constraints between
the interdependent processes in terms of semantic relationships. At run-time,
these coordination constraints must be enforced by a coordination process
instance. As the coordination of multiple interdependent processes is a complex
endeavor, several challenges need to be fulfilled to achieve optimal process
coordination. For example, processes must be allowed to run asynchronously and
concurrently, taking their complex relations into account. This paper
contributes the operational semantics of coordination processes, which enforces
the coordination constraints at run-time. Coordination processes form complex
structures to adequately represent processes and their relations, specifically
supporting many-to-many relationships. Based on these complex structures,
markings and process rules allow for the flexible enactment of the
interdependent processes while fulfilling all challenges. Coordination
processes represent a sophisticated solution to the complex problem of
coordinating interdependent, concurrently running processes.
