  System complexity has become ubiquitous in the design, assessment, and
implementation of practical and useful cyber-physical systems. This increased
complexity is impacting the management of models necessary for designing
cyber-physical systems that are able to take into account a number of
``-ilities'', such that they are safe and secure and ultimately resilient to
disruption of service. We propose an ontological metamodel for system design
that augments an already existing industry metamodel to capture the
relationships between various model elements and safety, security, and
resilient considerations. Employing this metamodel leads to more cohesive and
structured modeling efforts with an overall increase in scalability, usability,
and unification of already existing models. In turn, this leads to a
mission-oriented perspective in designing security defenses and resilience
mechanisms to combat undesirable behaviors. We illustrate this metamodel in an
open-source GraphQL implementation, which can interface with a number of
modeling languages. We support our proposed metamodel with a detailed
demonstration using an oil and gas pipeline model.
