Seminars

ME/IE 8773-8774
INDUSTRIAL ENGINEERING DIVISION SEMINAR
Operations Research
Host: : William L. Cooper

Response Times in M/M/s Fork-Join Networks

by

Richard F. Serfozo
Professor
School of Industrial and Systems Engineering
Georgia Institute of Technology

Wednesday, February 18, 2004
3:30-5:00 p.m.
Room 1130 ME
Coffee and cookies will be available at 3:15 p.m. before the seminar

Abstract: We will discuss a fork-join processing network in which jobs arrive according to a Poisson process, and each job splits into m tasks, which are simultaneously assigned to m nodes that operate like M/M/s queueing systems. When all of its tasks are finished, the job is completed. Such networks arise in manufacturing assemblies, supply chains and computer/ communications systems. The main result is a closed-form formula for approximating the distribution of the network’s response time (the time to complete a job) in equilibrium. We also present an analogous approximation for the distribution of the equilibrium queue length (the quantity of jobs in the system), when each node has one server. Extensive simulations led the way to the analytical results. Kolmogorov-Smirnov statistical tests show that these formulas are good fits for the distributions obtained from simulations. This is joint work with Sung-Seok Ko.

Bio: Richard F. Serfozo received a B.S. degree in Mathematics from Wayne State University (1961), an M.A. degree in Mathematics from the University of Washington (1965), and a Ph.D. degree in Industrial Engineering and Management Sciences from Northwestern University (1969). Since 1983, he has been a Professor in the School of Industrial and Systems Engineering at the Georgia Institute of Technology. He worked as an Operations Research Analyst at Bell Laboratories from 1969-1978, an Assistant and Associate Professor in Industrial Engineering and Operations Research at Syracuse University from 1978-1983, an Operations Research Analyst with The Boeing Company from 1962-1967, and a Product Engineer with Ford Motor Company in 1961. He has held Visiting Positions at Cornell University, Universität Karlshruhe, University of North Carolina, and Sao Paulo University. His research interests are in applied probability and stochastic processes, including stochastic networks in manufacturing and communications, extreme value theory, point processes, parallel simulation, Markov decision processes, control of queues, and design of service systems. He has served as Editor-in-Chief of Queueing Systems: Theory and Applications from 1995 to the present. He was Area Editor of Mathematics of Operations Research (1990–1996) and Associate Editor of Queueing Systems (1986-1994), Mathematics of Operations Research (1985-1990), and Operations Research (1977–1986). He was a panel member of the NSF Science and Technology Program (1988) and served was Chairman of ORSA/TIMS Applied Probability Group (1985–1986).

Informal Faculty Luncheon: Wednesday, February 18, 2004, 12:00 noon. Meet in 1100 ME and walk to lunch with other faculty. Prof. Serfozo will be able to attend