1. In a networked computer system having a workflow management system and a central policy management system, a method of operating the networked computer system to control workflow, comprising: creating, by the workflow management system, a workflow class definition; exporting, by the workflow management system, the workflow class definition to the central policy management system; creating, within the central policy management system, an access control policy for the workflow class; binding resources and roles to steps within the central policy management system, including: encapsulating security mechanism application specific information for each security mechanism, wherein encapsulating includes forming a key for each security mechanism; combining keys to form at least portions of policy as key chains in one or more semantic policy layers; associating workflow steps with the key chains; encapsulating key chains as keys and passing the key chain keys from a first semantic policy layer to a second semantic policy layer; importing a key chain from the second semantic policy layer to a local access policy layer; and enforcing the access control policy on the computer via the security mechanisms; creating, by the workflow management system, a workflow instance in both the workflow management system and the central policy management system; and executing the workflow instance within a computer.