Ralph L. Disney

February 27, 1928 – November 11, 2014

Brief Biography

Disney APS Presidential Portrait

Born in Baltimore, Maryland, Ralph L. Disney was a founder and former chairman of the Applied Probability College. As a teenager, he wrote for his high school’s newspaper and lettered in football, basketball, and baseball. Disney studied industrial and systems engineering at nearby Johns Hopkins University, receiving all three of his degrees from that institution. He played for the Hopkins baseball team, leaving the school in1948 due to financial reasons before returning in 1950.  As a graduate student, he worked with the Operations Research Office where he met his future wife, Lois Loghry DuFrain, one of the few women in OR at the time. Disney’s Doctor of Engineering dissertation, Some Problems in the Theory of Conveyors and Their Analysis by Method of Decomposition of Queueing Networks (1964), was supervised by Robert H. Roy and well-known probabilist Bruce Clarke.

Between his masters and his doctorate, Disney taught at Lamar University in Beaumont, Texas, enrolling one of the first black students in the college after the Supreme Court’s ruling on Brown v. Board of Education. This was a bold move at the time given the town’s disagreement with the decision. In 1959, he and his family moved to the University of Buffalo in New York and set up the school’s first computing laboratory. Disney was invited to be a Visiting Professor at the University of Michigan in 1962 and, after receiving his DEng, accepted a permanent position, eventually rising to Full Professor.

In restructuring the Industrial Engineering curriculum at Michigan, he developed new courses that resulted in the publication of two textbooks co-authored with Clarke. At Michigan, he developed close relationships with a number of his students including W. Peter Cherry. Disney went on to the Virginia Polytechnic Institute and State University in Blacksburg in 1977, helping build an internationally recognized program in queueing theory and applied probability. He left Virginia Tech to join the Faculty at Texas A&M in 1988, remaining until his 1996 retirement.  Over the course of his academic career spanning four decades and five universities, Disney graduated twenty PhD students and influenced countless others from around the world in a wide variety of operations research disciplines.

Disney served on the editorial boards of a number of publications, helping over one hundred and fifty authors get their works published. He was Senior Editor of the Industrial Engineering Institute’s research journal. With the Operations Research Society of America (ORSA) and The Institute of Management Sciences (TIMS), Disney created and led the Applied Probability College (today’s Applied Probability Society) in the 1970s.  He served on the Council of TIMS and ORSA’s successor, the Institute for Operations Research and the Management Sciences (INFORMS), and was named an inaugural Fellow of that organization in 2002.

Among the many honors he received in his lifetime, Disney was a Fellow and Albert G. Holzman Distinguished Educator Award winner of the Institute of Industrial Engineers. He was inducted into the National Academy of Engineering in 1999. Disney passed away at age eighty-six.

Other Biographies

Texas A&M Engineering. Industrial and Systems Engineering Faculty: Ralph L. Disney. Accessed May 15, 2015. (link)


Johns Hopkins University, BSE 1952

Johns Hopkins University, MSE 1955

Johns Hopkins University, PhD 1964 (Mathematics Genealogy)


Academic Affiliations
Non-Academic Affiliations

Key Interests in OR/MS



Texas A&M University Dwight Look College of Engineering. News: Industrial engineering loses an icon. Published November 20, 2014. Accessed July 10, 2018. (link)

University of Michigan Faculty History Project. Ralph L. Disney: Obituary/Memoir. Accessed July 12, 2018. (link)

Awards and Honors

Institute for Industrial Engineers Fellow 1981

Frank and Lillian Gilbreth Industrial Engineering Award 1993

National Academy of Engineering 1997

Institute for Operations Research and the Management Sciences Fellow 2002

Professional Service

Applied Probability Society, Chair 1981-1982

Selected Publications

Disney R. L. (1962) Some multichannel queueing problems with ordered entry. Journal of Industrial Engineering, 13(1): 46-48.

Clarke A. B. & Disney R. L. (1970) Probability and Random Processes for Engineers and Scientists. Wiley: New York.

Cherry W. P. & Disney R. L. (1973) Some Topics in Queueing Network Theory. University of Michigan Department of Industrial and Operations Engineering: Ann Arbor, MI. 

Cherry W. P. & Disney R. L. (1983) The suspension of two independent Markov renewal processes. Applicationes Mathematicae, 17(4): 567-602.

Disney R. L. & Konig D. (1985) Queueing networks: A survey of their random processes. SIAM Review, 27(3): 335-403.

Disney R. L. & Kiessler P. C. (1987) Traffic Processes in Queueing Networks: A Markov Renewal Approach. Johns Hopkins University Press: Baltimore, MD.

Disney R. L., Som P., & Wilhelm W. E. (1994) Kitting process in a stochastic assembly system. Queueing Systems, 17(3-4): 471-490.