P.C. Rossin College of
Engineering and Applied Science
Novel software leverages operations research for prison population management

A first-of-its-kind optimization model developed by Lehigh engineers—in collaboration with Pennsylvania’s Department of Corrections (PADOC)—has received the prestigious Daniel H. Wagner Prize for Excellence in Operations Research Practice for 2017.

The Inmate Assignment Decision Support System (IADSS), which was invented by students and faculty members in industrial and systems engineering, streamlines the assignment of inmates to Pennsylvania’s 25 correctional institutions and has been credited with saving the state millions of dollars.

IADSS can make hundreds of inmate assignments in a few minutes, a task that requires days when performed manually by humans. The system is the product of five years of work by faculty members Tamás Terlaky, Louis Plebani and George Wilson, as well as Ph.D. candidate Mohammad Shahabsafa, graduate student Anshul Sharma, Dan Li ’13 Ph.D. and Chatainya Gudapati ’17G.

PADOC officials say the Inmate Assignment Decision Support System (IADSS) has “transformed” the inmate assignment process in Pennsylvania and can do the same for state correctional agencies across the United States. In the long run, they say, the system could shorten prison stays and reduce recidivism by giving inmates more timely access to the treatment programs they need to earn parole.

There are currently 46,800 inmates in the state’s correctional institutions. PADOC’s annual expenditures total approximately $2.5 billion, or about 8 percent of the state’s total budget.

IADSS represents the first application of operations research to the assignment of prison inmates. In a report released in September 2017, PADOC officials said IADSS has enabled the corrections department to achieve cost savings and improvements in four areas:

  • Shorter waiting lists for treatment programs, which will reduce the length of time inmates remain in prison past their minimum sentence date;
  • Fewer prison assaults through improvement in assigning the right combination of inmates to the right prisons;
  • Fewer staff members needed to oversee inmate assignments and transfers; and,
  • A reduction in the need for transfers of inmates among prisons.

“Based on these four criteria,” the report said, “we believe that the IADSS has saved the PADOC, and thus saved Pennsylvania taxpayers, approximately $2.9 million during the first year, which will translate into approximately $19.2 million in savings over the next five years.”

The Wagner Prize is awarded by INFORMS (the Institute for Operations Research and the Management Sciences), the world’s premier professional association for analytics and operations research, and recognizes the application of “strong mathematics…to practical problems supported by clear and intelligible writing, the quality and coherence of analysis, [and] good writing, strong analytical content and verifiable practice successes.”

Terlaky, along with fellow editors Miguel F. Anjos of Polytechnique Montréal and Shabbir Ahmed of Georgia Institute of Technology, has also recently released a new textbook to "provide a solid foundation for engineers and mathematical optimizers alike who want to understand the importance of optimization methods to engineering, and the capabilities of these methods." Advances and Trends in Optimization with Engineering Applications, as published by the Mathematical Optimization Society (MOS) and the Society for Industrial and Applied Mathematics (SIAM) is volume 24 of a prestigious MOS-SIAM series on optimization. Topics covered by the series explore the theory and practice of optimization, discussing algorithms, software, computational practice, applications, and the links among these subjects.

The Inmate Assignment Decision Support System (IADSS), invented by students and faculty members in industrial and systems engineering, received the prestigious Daniel H. Wagner Prize for Excellence in Operations Research Practice for 2017. (Photo courtesy