Administration of access control was and still is a crucial, critical and complex aspect of Security Administration. Many models were developed and used to effect this administration such as Mandatory access Control (MAC), Discretionary Access Control (DAC) and Role Base access Control. the latter, RBAC which is a flexible and policy-independent access control, represents a natural structure of an organization where functions are grouped into roles and users are permitted to one or more of these roles. In large organizations with relatively large systems, with hundreds of roles and users and ...