A method for generating a system specific security-definition for a heterogeneous subsystem of a computing system is provided. A natural-language security-definition is stored in a rule-repository. A machine-readable security-definition is stored and a first mapping of a natural-language security-definition onto a machine-readable security-definition is stored in the rule-repository. A system-specific security-definition is generated from a machine-readable security-definition by a rule-converter that corresponds to a heterogeneous subsystem. The generation is based on a second mapping of each machine-readable security definition onto indications of system-specific security-definitions.