4 level architecture of IRDS by ISO
The IRD Definition Schema Level:
- A metametamodel according to which the IRD Definition level objects can be described.
- e.g. ‘concept’ (Wijers 1991) or OPRR’s ‘Object’ metatype (Smolander 1992).
- Schemata and application programs specs
- Metaclass level of languages such as Smalltalk.
- e.g. specification of UML
- DB schemata and app. programs
- Class level of class-based languages
- Application data and execution.
- Instances of class-based languages.
- e.g. Customer “Juha-Pekka”