A mature process for the development of embedded controls and systems using Model-Based Design relies on libraries of validated models for the physical system components. These models are used throughout the design process and are readily available to the system and controls engineers for design and validation tasks. Models are created at various levels of abstraction to accommodate analysis needs at various stages of the design process. Abstract models are used early in the process for quick assessment of design tradeoffs, while higher fidelity models are used as the design progresses to account for the dynamics that affect system performance. Once acceptable system performance is achieved with desktop simulation, the models are moved to a real-time platform for final verification. Creating real-time capable plant models typically requires making assumptions and compromises to achieve acceptable performance. The end result is successful deployment of the embedded controls system with minimal reliance on expensive prototype hardware during the bulk of the design process. This paper outlines the necessary requirements and key considerations in using plant models as part of Model-Based Design.