RO plant operators, end-users, membrane manufacturers and system suppliers have been facing two major problems since the advent of commercial membrane technology applications for water desalination utilizing reverse osmosis (RO) and other membrane processes: how to reliably monitor their membrane system performance and how to detect membrane fouling and scaling development in real time and before significant or irreversible loss of performance efficiency occurs, resulting in lower plant availability and significantly higher O&M costs. The current industry-standard performance analysis and evaluation technique is based on trending RO flux decline characteristics of membranes via normalizing system operating data in accordance with ASTM D-4516 standard method. This AA paper discusses the shortfalls of this technique, and introduces a practical new technology for measuring and monitoring membrane fouling and flux performance in real-time. The new Silent Alarm(TM) technology, designed as an early-warning system, allows the discovery of any fouling or scaling development on the RO membranes in the very early stages, thus providing a valuable tool for the plant operator to take immediate corrective measures before it is too late. Two major brackish and seawater Arabian Gulf RO plant case studies with and without a fouling history are discussed. This proven capability to monitor RO plant performance in real-time and measure the actual development of any membrane fouling or scaling very early on has a direct and dramatic positive impact on optimizing the total cost of desalinated water.