Efficient multi-disciplinary analysis and optimization (MDAO) of aerospace vehicles is enabled by the generation of parametric, feature-based models. Many systems for generating these vehicles have been developed over the past decades, but most of these systems focus on the development of models that are well suited to the manufacturing process. Recently, the Engineering Sketch Pad (ESP) was introduced whose expressed purpose is the generation of models for aerospace design and analysis. Three of the key features of ESP are its ability to develop multiple, linked models for use throughout the design process, to utilize user-defined features that are central to aerospace vehicles (such as airfoils, flaps, and spoilers), and to compute analytic sensitivities for optimization and uncertainty quantification. Contained herein is a description of ESP, including those components that directly support the above. In particular, the use of ESP to generate models within a single discipline that are used in the conceptual, preliminary, and final design stages is reviewed. Similarly, multiple linked models in cooperating disciplines are also discussed. These concepts are demonstrated on a sample transport configuration.