Access Control Designer is a universal modular tool for visually designing access control policies. The user of this system depicts requirements for the designed security policy in a graphical notation based on a generally accepted security model. The tool will then generate a configuration of security mechanisms, which will be used for the implementation of the security policy. Modularity of the tool will allow users to design security policies for a lot of various environments - systems needed to have access controlled. A pluggable module API allows third-party programmers to provide ACD modules for systems and so allow users to use ACD for designing access control policies for the systems.