The modeling and enactment of business processes is being recognized as key to modern information managment. The expansion of Web services has increased the attention given to processes, because processes are how services are composed and put to good use. However, current approaches are inadequate for flexibly modeling and enacting processes. These approaches take a logically centralized view of processes, treating a process as an implementation of a composed service. They provide low-level scripting languages to specify how a service may be implemented, rather than what interactions are expected from it. Consequently, existing approaches fail to adequately accommodate the essential properties of the business partners in a process (the partners would be realized via services)---their autonomy (freedom of action), heterogeneity (freedom of design), and dynamism (freedom of configuration).Flexibly represented protocols can provide a more natural basis for specifying processes. Protocols specify what rather than how; thus they naturally maximize the authonomy, heterogeneity, and dynamism of the interacting parties. We are developing an approach for modeling and enacting business processes based on protocols. This paper describes some elements of (1) a conceptual model of processes that will incorporate abstractions based on protocols, roles, and commitments; (2)the semantics or mathematical foundations underlying the conceptual model and mapping global views of processes to the local actions of the parties involved; (3) methodologies involving rule-based reasoning to specify processes in terms of compositions of protocols.