It is critical to evaluate the quality-of-service (QoS) properties of enterprise distributed real-time and embedded (DRE) system early in their lifecycle-instead of waiting until system integration-to minimize the impact of rework needed to remedy QoS defects. Unfortunately, enterprise DRE system developers and testers often lack the necessary resources to support such testing efforts. This chapter discusses how test clouds (i.e., cloud-computing environments employed for testing) can provide the necessary testing resources. When combined with system execution modeling (SEM) tools, test clouds can provide the necessary toolsets to perform QoS testing earlier in the lifecycle. A case study of design and implementing resource management infrastructure from the domain of shipboard computing environments is used to show how SEM tools and test clouds can help identify defects in system QoS specifications and enforcement mechanisms before they become prohibitively expensive to fix. © 2013, IGI Global.