Henderson-Sellers, BrianGonzalez-Perez, CesarBrockmans, SaartjeJung, JürgenSure, York2019-06-042019-06-042006978-3-88579-190-4https://dl.gi.de/handle/20.500.12116/23468Metamodelling is an increasingly prevalent tool in conceptual modelling – in particular in the context of OMG standards such as UML, MOF and SPEM. However, when applying a standard metamodelling approach based solely on instantiation semantics, many problems arise. These are shown to be solved using a powertype-based approach instead. Here we summarize this approach and focus on the ease with which this meta-architecture can be extended to support additional attributes and subtypes. This extensibility is readily accommodated within the strictures of the new metamodel without the need to invoke extension mechanisms such as stereotypes and profiles (as is currently advocated in the UML and SPEM).enText/Conference Paper1617-5468