Business processes �the next generation workflows- have attracted considerable research interest in the last fifteen years. More recently, several XML-based languages have been proposed for specifying and orchestrating business processes, resulting in the WS-BPEL language. Even if WS-BPEL has been developed to specify automated business processes that orchestrate activities of multiple Web services, there are many applications and situations requiring that people be considered as additional participants that can influence the execution of a process. Significant omissions from WS-BPEL are the specification of activities that require interactions with humans to be completed, called human activities, and the specification of authorization information associating users with human activities in a WS-BPEL business process and authorization constraints, such as separation of duty, on the execution of human activities. This talk investigates the problem of access control and resiliency for WS-BPEL processes. Access control in the context of business process means checking whether a user claiming the execution of an activity is authorized and the execution does not violate authorization constraints. Resiliency means that even if some users become unavailable, the remaining users can still complete the execution of the process according to the stated authorizations and authorization constraints. We present RBAC-WS-BPEL, an RBAC model for WS-BPEL business processes that supports the specification of resiliency constraints, authorizations and authorization constraints on business process activities. Resiliency constraints are evaluated when a WS-BPEL process is deployed, to check if there is a sufficient number of authorized users to perform the process so that authorization constraints are satisfied and the process terminates even if some users become unavailable. Authorizations and authorization constraints are evaluated whenever a user claims the execution of a business process�s activity to determine if the execution of the activity by the user does not violate any authorization constraints and does not prevent some other subsequent activities from completing.