Business process management and systems have been proven mature and highly beneficial in many domains. Recent surveys by leading market analysts say that the next challenge for BPM are unstructured processes. Based on a domain study in disaster response management, we identify current shortcomings of business process models and management with respect to unstructured processes. We develop a generic model for flexible temporal ad-hoc coordination of activities. Its focus lies on awareness and feedback as well as loosely structuring the process with temporal dependencies. It is implemented as an extension to the open Google Wave collaboration infrastructure. The approach is commented by commanders in the disaster management domain.