According to some embodiments, a visual design tool associated with a generic modeling framework may be selected, and a set of design-time functions used in the visual design tool may be identified. A set of design-time rules may be created (e.g., by a rule creator), each rule corresponding to an identified design-time function. In addition, parameters may be defined for each rule in terms of entities of a language of the generic modeling framework. A set of basic rule cases may then be defined for each rule to specify rule logic, and an extension mechanism may be provided to enable the defined set of basic rule cases to be extended outside the generic modeling framework. According to some embodiments, the set of rules and associated basic rule cases may be interpreted at run-time by the modeling framework.