Conducting uncertainty analysis has become a requirement before making high-risk, capital-intensive decisions in oil and gas projects. Often, the key technical risks that affect project success are caused by subsurface uncertainties. Better use of probabilistic approaches to reservoir performance forecasting can help provide increased value from subsurface models. Martha Stunell holds a bachelor's in both geology and psychology from Amherst College in Massachusetts and an MSc in petroleum engineering from Stanford University in California. She has been working as a reservoir engineer in Schlumberger for 17 years and has championed the development and deployment of uncertainty analysis technology since 2003. Sanjoy Khataniar has more than 30 years of experience in the oil and gas industry working as a reservoir engineer and a reservoir modeling and simulation technology consultant. He holds two degrees in petroleum engineering: a bachelor's from the Indian School of Mines in Dhanbad and an MSc from the Norwegian University of Science and Technology (NTNU) in Trondheim.