—Deploying a security policy may prove difficult whenever the system does not embed all necessary security functionalities. Some specific functionalities are required to accurately evaluate the contexts viewed as constraints in which some security requirements are to be met. Dynamic or contextual requirements are problematic since they rely on specific functionalities which are not always available in the system or are even impossible to acquire given the current technologies. Therefore, it is essential to ensure that the contextual requirements are always managed and well deployed taking into account the existent functionalities in the system. We present a solution to cope with the following issue: ensuring that the contextual security requirements are always best deployed within the set of functionalities in the system. Keywords-access control; policy model and contexts; optimization.