Software complexity may be reduced and productivity may be increased by the synergy of Component-Based Software Product Line (SPL) Engineering. When applied to Distributed Real-time and Embedded (DRE) systems, these technologies must fulfill systems' time- critical missions and numerous functional and Quality of Service (QoS) requirements. New critical challenges to be solved are QoS sensitivity that influences functional validity and performance quality, tangled requirements that increase the complexity of requirements evaluation and abundant unsatisfactory design artifacts that introduce unnecessary workload. To answer such challenges, this book introduces an SPL approach for DRE systems. The approach comprises (1) Domain Engineering: Analyze QoS requirements and their commonalities; (2) Application Engineering: Model behavioral characteristics of DRE systems; and (3) Quantitative Analysis: Simulate the influence factors of deployment environments and search optimal simulation results. The book provides two case studies and experimental results to show the benefits of using our approach for DRE design space exploration and software construction.