Walter Scott, Jr. College of Engineering

Dr. William S. Duff

Emeritus Professor

Mechanical Engineering

In 2015, after 44 years of service, Dr. Duff formally retired from the department. He maintains a limited research agenda with several current and former M.S. and Ph.D. students. Dr. Duff has published over 180 journal articles and conference papers and served as an associate journal editor. He created 15 new courses, taught 26 different courses, and has been the major professor for over 60 masters students and 25 Ph.D. students. Dr. Duff headed the department’s Industrial Engineering and Operations Research and Engineering Management undergraduate and graduate programs for 36 years, chaired the college Systems Engineering and Optimization committee for 15 years. He served on university committees for nine years, where he established the university’s current Latin Honors awarding procedures and was a primary contributor in establishing the initial university formal procedures on academic dishonesty. He organized and managed International Energy Agency Solar Heating and Cooling Task programs and projects for 19 years. Dr. Duff also spent seven years at the University of Chicago Department of Physics Enrico Fermi Institute and a year at the Philips research laboratory in Aachen, Germany. He started two companies, helped start two others, and served on the board of directors for four companies and two academic societies.


  • Ph.D. 1971, Stanford University—Industrial Engineering
  • M.S. 1968, Stanford University—Statistics
  • M.B.A. 1965, University of Pennsylvania, Wharton School of Finance and Commerce—Business Administration
  • B.S. 1961, Cornell University—Mechanical Engineering


Research Interests

  • Mathematical Modeling, Optimization and Statistical Analysis
  • Simulation
  • Economic Modeling and Analysis
  • Concentrating Solar Thermal Power and Photovoltaics
  • Residential and Commercial Solar Heating and Cooling Systems and Evacuated Solar Collectors

Honors and Awards

  • Selection of as one of the decade’s best publications by the International Society for Optical Engineering
  • Awarded a United States patent for an innovation in non-imaging solar collector optics
  • Selection of his organized and managed 13-country research project as the most effective research effort overseen by the International Energy Agency Solar Heating and Cooling Executive Committee
  • MBA with Second Year Honors, University of Pennsylvania Wharton School
  • Selected as one of two out of over about 800 Wharton MBAs as a Research Fellow at the University of Pennsylvania’s Management Science Center