NASA has developed an advanced arrival management capability for terminal controllers, known as Terminal Sequencing and Spacing (TSS). TSS increases use of performance-based navigation (PBN) arrival procedures during periods of high traffic demand. It enhances two Federal Aviation Administration operational systems with terminal metering and controller spacing tools. Sixteen high-fidelity human-in-the-loop simulations, involving more than five hundred hours of evaluation time, were conducted to mature TSS from proof-ofconcept design to fully functional prototype. These simulations modeled arrival procedures at several U.S. airports, incorporated a broad range of traffic demand profiles and wind conditions, and used controllers with extensive operational experience. Two metrics are evaluated for these simulations: PBN Success Rate and Inter-Arrival Spacing Error. The PBN Success Rate shows a definitive trend when TSS is used. It increases from 42% for today's operations to 68% for terminal metering only and 92% for terminal metering with controller-managed spacing tools. Meanwhile, the Inter-Arrival Spacing Error improves 25-35% when TSS is used compared to not used. The TSS technology was transferred to the FAA, and it is targeted for deployment to several busy airports in the United States starting in 2018.