Applied Stochastic and Statistical Modelling Lab (SSL)

Vahid Sarhangian

Associate Professor, Mechanical & Industrial Engineering
Director, Centre for Healthcare Engineering (CHE)

Email: sarhangian AT mie DOT utoronto DOT ca
Homepage: https://sarhangian.mie.utoronto.ca/
Campus Phone: (416) 978 – 4020
Office Location: BA8108 (Bahen Centre),
40 St George St, Toronto, ON M5S 2E4

About me

I am an Associate Professor at the Mechanical and Industrial Engineering (MIE) department, and the Director of the Centre for Healthcare Engineering (CHE) at the University of Toronto. I did my PhD studies in Operations Management and Statistics at the Rotman School of Management at University of Toronto. Before joining MIE, I was a Postdoctoral Research Scholar at the division of Decision, Risk, and Operations at Columbia Business School.

My current research focuses on sequential (dynamic) decision-making under uncertainty with applications to healthcare, service, and forestry operations.

Research

  • Working papers
  1. Z. Zhang, D. Wang, N. Chen, R. Mansur, V. Sarhangian, Comparing Exploration-Exploitation Strategies of LLMs and Humans: Insights from Standard Multi-armed Bandit Tasks.
  2. W. Xing, Y. Hu, A. Kalvit, V. Sarhangian, Online learning for dynamic service mode control.
  3. J. Dong, B. Gorgulu, V. Sarhangian, Multiclass queue scheduling under slowdown: An approximate dynamic programming approach.
  4. T. C. Y. Chan, J. Park, V. Sarhangian, Dynamic transfer policies for parallel queues.
  5. Jangwon Park: Second place, 2024 CORS Queueing and Applied Probability SIG Student Paper Competition
  6. P. Afeche, J. Hu, R. Ibrahim, V. Sarhangian, The effects of information granularity on abandonment and congestion in non-stationary priority queues.
  7. P. Afeche, V. Sarhangian, Rational abandonment from priority queues: equilibrium strategy and pricing implications.
  • Published/Accepted papers
  1. T. C. Y. Chan, J. Park, F. Pocagar, V. Sarhangian, E. Hellsten, F. Razak, A. Verma, Optimizing inter-hospital patient transfer decisions: a queueing network approach. Manufacturing & Service Operations Management (M&SOM). Forthcoming.
    • Jangwon Park: First place, 2024 CORS Healthcare SIG Student Paper Competition.
  2. T. C. Y. Chan, J. Park, V. Sarhangian, Robust confidence bands for stochastic processes using simulation. Operations Research Letters, Forthcoming.
  3. Y. Ravid, R. Ibrahim, J. Hu, K. Pasupathy, D. M. Nestler, V. Sarhangian, and P. Afèche. “Predicting left-without-being-seen in an emergency department as a dynamic risk.” The American Journal of Emergency Medicine (2025).
  4. R. Stephenson, V. Sarhangian, S. Cheskes, L. Turner, B. Nolan, I. Drennan, T. CY Chan, and J. Von Vopelius-Feldt. “Feasibility and optimization of a second-tier prehospital critical care response for major trauma in a North American urban and suburban area: A geospatial analysis and modelling study.” The American Journal of Emergency Medicine (2025).
  5. J. Chiu, V. Sarhangian, S. Tosoni, L. D. Pozzobon, L. B. Chartier, Associations of hospital unit occupancy with inpatient falls and fall-risk assessment completion: a retrospective cohort study. International Journal for Quality in Health Care, 2025.
  6. H. Abouee-Mehrizi, M. Mirjalili, V. Sarhangian, Platelet inventory management with approximate dynamic programming. INFORMS Journal on Computing, To appear. [code]
  7. M. Naghshbandi, S. Y Huang, H. Shah, C. Yim, E. Lee, M. Caesar, A. Hope, T. C. Y. Chan, V. Sarhangian, Evaluation of a nurse practitioner-led post-discharge transitional care program for patients with liver disease: A retrospective cohort study. Canadian Liver Journal, 2024.
  8. T. C. Y. Chan, S. Y. Huang, V. Sarhangian, Dynamic control of service systems with returns: Application to design of post-discharge hospital readmission prevention programs. Operations Research, Forthcoming. [code]
  9. J. Chan, B. Gorgulu, V. Sarhangian, Inventory management with advance booking information: the case of surgical supplies and elective surgeries, Manufacturing & Service Operations Management, 2024.  [code]
  10. J. Dong, B. Gorgulu, V. Sarhangian, What causes delays in admission to rehabilitation care? a structural estimation approach, Manufacturing & Service Operations Management, 2024.
  11. R. Stephenson, V. Sarhangian, J. Park, A. Sankar, N. N. Baxter, T. A. Stukel, A. N. Simpson, D. N. Wijeysundera, A. S. Wilton, C. de Mestral, S. W. Hang, D. Pincus, R. J. Campbell, D. R. Ubrach, J. Irish, D. Gomez, T. C. Y. Chan, “Evolution of the surgical procedure gap during and after the COVID-19 pandemic in Ontario, Canada: cross-sectional and modelling study“. British Journal of Surgery, 2023.
  12. M. Mirjalili, H. Abouee-Mehrizi, R. Barty, N. M. Heddle, V. Sarhangian, A data-driven approach to determine daily platelet order quantities at hospitals. Transfusion, 2022.
  13. C. W. Chan, V. Sarhangian, P. Talwai, K. Gogia, Utilizing partial flexibility to improve emergency department flow: theory and implementation. Naval Research Logistics, 2022.
  14. Winner: Kuhn Award 2024
  15. H. Abouee-Mehrizi, M. Mirjalili, V. Sarhangian, Data-driven platelet inventory management under uncertainty in the remaining shelf-life of units. Production and Operations Management, 2022.
  16. B. Gorgulu, J. Dong, K. Hunter, K. Bettio, B. Vukusic, J. Ranisau, T. Tang, V. Sarhangian, Association between delayed discharge from acute care and rehabilitation outcomes and length-of-stay: a retrospective cohort study. Archives of Physical Medicine and Rehabilitation, 2022.
  17. J. Toor, I. Saleh, A. Abbas, J. Abouali, P. Wong, T. C. Y. Chan, V. Sarhangian, An anesthesia block room is financially net positive for a hospital performing arthroplasty. Journal of the American Academy of Orthopaedic Surgeons, 2022.
  18. M. Anderson, M. Bodur, S. Rathwell, V. Sarhangian, Optimization helps scheduling nursing staff at the long-term care homes of the city of Toronto. INFORMS Journal of Applied Analytics, 2023.
  19. B. Gorgulu, V. Sarhangian, A Newsvendor approach to design of surgical preference cards. Service Science, 2022.
  20. C. W. Chan, M. Huang, V. Sarhangian, Dynamic server assignment in multiclass queues with shifts, with applications to nurse staffing in emergency departments. Operations Research, 2021.
  21. J. Sismondo, V. Sarhangian, E. Borg, E. Roberge, F. H. Berger, Emergency imaging after a mass casualty incident: an operational perspective via a simulation study, Proceedings of the 2020 Winter Simulation Conference, 2021.
  22. Best Contributed Applied Paper – Finalist
  23. V. Sarhangian, H. Abouee-Mehrizi, O. Baron, O. Berman, Threshold-based allocation policies for inventory management of red blood cells, Manufacturing & Service Operations Management, 2017.
  24. V. Sarhangian, H. Abouee‐Mehrizi, O. Baron, O. Berman, N. M. Heddle, R. Barty, Reducing the age of transfused red blood cells in hospitals: ordering and allocation policies, Vox sanguinis, 2016.
  25. V. Sarhangian, B. Balciog̃lu, A first passage time problem for spectrally positive Lévy processes and its application to a dynamic priority queue, Operations Research Letters, 2013.
  26. V. Sarhangian, B. Balciog̃lu, Waiting time analysis of multi-class queues with impatient customers, Probability in the Engineering and Informational Sciences, 2013.

Professional Activities

  • Associate editor for journals: INFORMS Journal on Computing, Decision Science, Healthcare Management Science.
  • Reviewer for journals: Operations Research, Stochastic Systems, Management Science, Manufacturing & Service Operations Management, Stochastic Models, Decision Science, Production and Operations Management, Service Science, Naval Research Logistics, Healthcare Management Science, INFORMS Journal on Computing, Journal of the Operational Research Society.
  • Professional Memberships: CORS, INFORMS