This paper describes the adoption of a usage model-driven platform definition process at Intel in three case studies: mobile platform thermal design, cross-platform manageability, and enterprise information management. It illustrates how usage models are defined and used to characterize platform workload, identify performance bottlenecks, optimize thermal design, and identify new platform capabilities. In the first case study, we focus on how usage models help us predict workloads on mobile platforms and how they help us define the right thermal design to address the diverse user needs for mobile platforms. In the second and third case studies, we analyze enterprise user needs for more agile IT and business processes. Based on the top usage models developed to address these needs, a set of cross-platform capabilities is defined to guide our platform definition.