International Journal of Computer Science and Security (IJCSS) Volume 2, Issue 2, April 2008.

Role -based access control (RBAC) has been introduced in the last few years, and offers a powerful means of specifying access control decisions. The model of RBAC usually assumes that, if there is a role hierarchy then access rights are inherited upwards through the hierarchy. In organization workflow the main threat is of access control. The Role based access control is one of the best suitable access control model one can think of. It is not only the role hierarchies but also other control factors that affect the access control in the workflow. The paper discusses the control factors and role hierarchies in workflow and brings a new model of RBAC. This paper also over comes the conflicts and proves that the system is safe by applying the new model to the workflow.