Complex business networks such as supply chains, with cross-organizational workflows of even greater complexity, are becoming increasingly common. The problem of engineering cross-organizational processes in a manner that accounts for inter-organizational constraints, and dynamics, has received little attention in the literature. This paper describes an effective framework for addressing the problem. The actor eco-systems approach leverages the ecosystems metaphor to model cross-enterprise constraints, change propagation and equilibria. It describes how cross-enterprise processes can be derived from such models and maintained in the face of dynamic business contexts.