This paper describes the implementation, testing, and performance of phasor measurements in an industrial state estimation at the New York Power Authority (NYPA). Phasor Measurement Units (PMU) with GPS synchronization were incorporated into the data acquisition subsystem of the Energy Management System (EMS). The modified State Estimator was subjected to pre-and post-field installation testing. The pre-field installation testing was done to verify the correctness of the solution algorithm, to identify the impact of phasor metering accuracy on the quality of estimator solution, to show the relative effectiveness of phasor measurements with respect to other measurements, to identify the effect of the reference bus selection, to detect the impact of PMUs on the State Estimator convergence, and to establish the minimum clock synchronization sampling accuracy required for the PMUs [10]. The post-field installation tests were conducted to identify the effectiveness of the PMUs in the State Estimator solution using the real-time data as well as to detect the effect of time skewing and measurement weights on the State Estimator solution. and since then has been involved in development and implementation of Advanced Application software. His area of interest is robust estimation, power system analysis and control, graph theory, and parallel processing. Note: The opinions and views offered here are my own and not necessarily those of the United States, the Federal Energy Regulatory Commission, individual Commissioners, or other members of the Commission staff. Behruz (Bruce) Fardanesh received his B.S. in Electrical Engineering from Sharif University of Technology in Tehran, Iran in 1979. He also received his M.S. and Doctor of Engineering degrees both in Electrical Engineering from the University of Missouri-Rolla and Cleveland State University in 1981 and 1985, respectively. Since 1985 he has been teaching at Manhattan College where he holds the rank of Associate Professor of Electrical Engineering. Currently, he is also working in the area of Advanced Power Delivery in Research and Technology Development at the New York Power Authority. His areas of interest are power systems analysis, dynamics, control and operation.