Specifying and/or enforcing a domain model can include generating a pictorial diagram specifying a rule within a development environment, wherein the pictorial diagram includes a first subject element specifying criteria for selecting artifacts within the development environment. The pictorial diagram can be enabled within the development environment. Responsive to an execution event, the pictorial diagram can be executed by selecting each artifact matching the criteria of the first subject element and performing the rule specified by the pictorial diagram upon each selected artifact within the development environment.