  Model-based systems engineering (MBSE) provides an important capability for
managing the complexities of system development. MBSE empowers the formalisms
of system architectures for supporting model-based requirement elicitation,
specification, design, development, testing, fielding, etc. However, the
modeling languages and techniques are quite heterogeneous, even within the same
enterprise system, which creates difficulties for data interoperability. The
discrepancies among data structures and language syntaxes make information
exchange among MBSE models even more difficult, resulting in considerable
information deviations when connecting data flows across the enterprise. For
this reason, this paper presents an ontology based upon graphs, objects,
points, properties, roles, and relationships with entensions (GOPPRRE),
providing meta models that support the various lifecycle stages of MBSE
formalisms. In particular, knowledge-graph models are developed to support
unified model representations to further implement ontological data integration
based on GOPPRRE throughout the entire lifecycle. The applicability of the MBSE
formalism is verified using quantitative and qualitative approaches. Moreover,
the GOPPRRE ontologies are generated from the MBSE language formalisms in a
domain-specific modeling tool, \textit{MetaGraph} in order to evaluate its
availiablity. The results demonstrate that the proposed ontology supports both
formal structures and the descriptive logic of the systems engineering
lifecycle.
