A meta-model for creating models of alternative physical representations of logically equivalent entities, such as alternative wire format representations of logically equivalent messages, includes a logical meta-model and a physical meta-model. The logical meta-model provides logical entity component classes for creating a logical model which describes, in a platform and programming language neutral manner (e.g. as an XML schema), the logical structure of the modeled entity as a hierarchy of logical entity components. The physical meta-model provides classes for creating a physical model which describes the alternative physical representations. The physical meta-model includes Base Classes representative of generic physical representations of the logical entity components, with "correspondence associations" being defined between the Base Classes and corresponding logical entity component classes. The physical meta-model further includes at least one set of physical representation-specific, Derived Classes descendent from the Base Classes.