I've been a Research Staff Member at IBM Research for over 39 wonderful years, starting in 1968 at the San Jose (now Almaden) Research Lab, and since 1976 at the T. J. Watson Research Center, where I am currently an Associate Director of Computer Science. I also was a visiting professor in UCLA's Computer Science department for the 1981 - 1982 academic year. My research has been in the areas of computer performance modeling and analysis, queueing networks and statistical simulation methodology. I have published over 40 papers in these areas, as well as the Computer Performance Modeling Handbook (Academic Press, 1983). Recently, I led the establishment of the IBM Open Collaborative Research program that is spurring innovation in open source software through collaborative research projects between IBM and universities.

I am a Fellow of the ACM and IEEE, a recipient, with Martin Reiser, of the 1991 IEEE Koji Kobayashi Computers and Communications Award for my contributions to performance modeling and a recipient of the 2005 ACM SIGMETRICS Achievement Award. One of my main contributions was the development, with Martin Reiser, of the Mean Value Analysis algorithm for queueing networks (Mean Value Analysis of Closed Multichain Queueing Networks; Journal of the ACM, Vol. 27, No. 2, Apr. 1980). I've been an associate editor of the IEEE Transactions on Computers, an area editor of the Journal of the ACM and vice chairman of IFIP Working Group 7.3 on Computer Performance Modeling.

For the past several years I have been involved in fostering more ground breaking computer science research in IBM and in enhancing the professional lives of our researchers. In this regard, I established and head the Adventurous Research Program that supports long-term high risk, high payoff computer science research (The AR program is now folded into the Exploratory Research program). I also helped establish professional interest communities of IBM researchers worldwide in 30 computer science disciplines. These communities are modeled on the ACM Special Interest Groups.