Abstract: A computer system is described for representing and enforcing configuration rules that can be used to create and define a configuration or hardware definition for the computer system. The computer system represents configuration rules that define a configuration of a high end mainframe, such as an OS2200 system, in a file external to a configuration program with which a user may interact to manage the configuration of the mainframe system, and to enforce the configuration rules as a user is attempting to modify a configuration of a computer system. The configuration rules may be specified in, for example, an extensible markup language (XML) file format rather than in the source code of the executable program. The external configuration file may conform to a scripting language that allows a developer to embed validation operations for the configuration data specified in the XML file.