Professor Guillermo Gallego joined Columbia University's Industrial Engineering and Operations Research Department in 1988 where he has been conducting research in the areas of inventory theory, supply chain management, revenue management, and semi-conductor manufacturing. His work has been supported by numerous industrial and government grants. Professor Gallego has published influential papers in the leading journals of his field where he has also occupied a variety of editorial positions. Professor Gallego has consulted for large corporations such as IBM, Lucent, and Northwest Airlines, and government agencies such as the National Research Council and the National Science Foundation. His graduate students are associated with prestigious universities. He spent his 1996–97 sabbatical at Stanford University and was a visiting scientist at the IBM Watson Research Center from 1999 to 2003. He was the chairman of the IEOR Department from July 2002 to June 2008.