David P. Chassin is the manager for Electric Power Systems Engineering at Pacific Northwest National Laboratory where he has worked since 1992. He was Vice-President of Development for Image Systems Technology from 1987 to 1992, where he pioneered a hybrid raster/vector computer aided design (CAD) technology called CAD Overlay(R). He led the development of building energy simulation and diagnostic systems, including Softdesk Energy and DOE's Whole Building Diagnostician. His recent research focuses on load modeling and the application of agent-based simulations to modeling the smart grid. He manages the development of GridLAB-D(TM), an open source simulation of the smart grid design and built by PNNL for the US Department of Energy. He is a member of the Western Electricity Coordinating Council's (WECC) Market Integration Committee and contributes to WECC Load Modeling Task Force and the North American Electricity Reliability Council (NERC) Load Forecasting Work Group.