Concurrent part and process design has been shown to reduce product development time and cost. With modeling support it can also lead to improvements in product quality by providing design engineers with an understanding of manufacturing capability, not in terms of nominal constraints, but in terms of variation. In this paper we outline an approach to concurrent design based on a combination of manufacturing process variation models that we call the Integrated System Model (ISM). The ISM can be used to simultaneously choose combinations of design and manufacturing variables that result in minimal variation for the final product. We explore this approach through an example drawn from sheet metal part manufacturing in the aerospace industry.