Ohad Perry's Homepage

Ohad Perry

Associate Professor
Industrial Engineering and Management Sciences
McCormick School of Engineering
Northwestern University

Contact information

Email: ohad.perry@northwestern [dot] edu

Phone: (847) 467-4443

Fax: (847) 491-8005


Department of Industrial Engineering & Management Sciences
2145 Sheridan Road, Room C250
Evanston, IL 60208


B.Sc., Mathematics and Statistics, University of Haifa   (summa cum laude),  2004.

M.S., Operations Research, IEOR Department, Columbia University,   2005.

Ph.D., IEOR Department, Columbia University,   2010.              Doctoral Dissertation    (Adviser: Ward Whitt.)

Research interests

Stochastic systems and applied probability with applications to service, healthcare and inventory systems;   Performance analysis, control and stability of stochastic systems

Published & Accepted Papers

Students appear first and in bold

  • Hu Y., Dong J., Perry O.   "Asymptotic Optimality of the Binomial-Exhaustive Policy for Polling Systems with Large Switchover Times".   The Annals of Applied Probability, forthcoming.   (Winner of the 2020 APS Best Student Paper Award)

  • Moyal P., Perry O.   "Many-Server Limits for Service Systems with Dependent Service and Patience Times.   Queueing Systems, forthcoming.  

  • Wu A., Bassamboo A., Perry O.   "When Service Times Depend on Customers' Delays: A Relationship Between Two Models of Dependence".   Operations Research, forthcoming.  

  • Mayampurath A., Parnianpour Z., Richards C.T., Meurer W.J., Lee J., Ankenman B., Perry O., Mendelson S.J., Holl J.L., Prabhakaran S.   "Improving Prehospital Stroke Diagnosis Using Natural Language Processing of Paramedic Reports".   Stroke, forthcoming.  

  • Yu L., Iravani S., Perry O.   "A Fluid-Diffusion-Hybrid Limiting Approximation for Priority Systems with Fast and Slow Customers".   Operations Research, forthcoming.  

  • Hu Y., Dong J, Perry O., Cyrus M.R., Gravenor S., Schmidt J.M.   "Implementation of a patient-flow model to optimize inpatient hospital capacity".   The Joint Commission Journal on Quality and Patient Safety, forthcoming.  

  • Moyal P., Perry O.   "Stability of Parallel Server Systems".   Operations Research, forthcoming.  

  • Dong J., Perry O.   "Queueing Models for Patientflow Dynamics in Inpatient Wards".   Operations Research, 68(1), 2020. pp. 250-275.  

  • Wu A., Bassamboo A., Perry O.   "Service Systems with Dependent Service and Patience Times".   Management Science, 65(3), 2019. pp. 1151-1172.

  • Den Boer A., Perry O. and Zwart B.   "Dynamic Pricing Policies for an Inventory Model with Random Windows of Opportunities".   Naval Research Logistics, 65(8), 2018, pp. 660-675.

  • Moyal P., Perry O.   "On the Instability of Matching Queues".   Annals of Applied Probability, 27(6), 2017, pp. 3385-3434.

  • Perry O., Whitt W.   "Chattering and Congestion Collapse in an Overload Switching Control".   Stochastic Systems, 6(1), 2016, pp. 132-210.

  • Pang G., Perry O.   "A Logarithmic Safety Staffing Rule for Contact Centers with Call Blending".   Management Science, 61(1), 2015, pp. 73-91.

  • Perry O., Whitt W.   "Achieving Rapid Recovery in an Overload Control for Large-Scale Service Systems".   INFORMS Journal on Computing, 27(3), 2015, pp. 491-506.

  • Perry O., Whitt W.   "Diffusion Approximation for an Overloaded X Model Via a Stochastic Averaging Principle".   Queueing Systems, 76(4), 2014, pp. 347-401.  

  • Perry O., Whitt W.   "A Fluid Limit for an Overloaded X Model Via a Stochastic Averaging Principle".   Mathematics of Operations Research, 38(2), 2013, pp. 294-349.     

  • Gurvich I., Perry O.   "Overflow Networks: Approximations and Implications to Call-Center Outsourcing".   Operations Research, 60(4), 2012, pp. 996-1009.

  • Perry O., Whitt W.   "An ODE for an Overloaded X Model Involving a Stochastic Averaging Principle".   Stochastic Systems, 1(1), 2011, pp. 59-108.  

  • Perry O., Whitt W.   "A Fluid Approximation for Service Systems Responding to Unexpected Overloads".   Operations Research, 59(5), 2011, pp. 1159-1170.

  • Perry O., Whitt W.   "Responding to Unexpected Overloads in Large-Scale Service Systems".   Management Science, 55 (8), 2009, pp. 1353-1367.  

  • Grants

  • 2014-2017. National Science Foundation (NSF), CMMI 1436518 (PI). Service Systems with Outbound Work and Blending. $296,011.

  • July-August 2017. Northwestern Memorial Hospital (NMH). Capacity Sizing of Inpatient Units at NMH. With Jing Dong. Implemented our model for patient-flow in inpatient units. $49,382.

  • 2018-2021. National Science Foundation (NSF), CMMI 1763100 (PI). GOALI: Improving Patient Flow in Hospitals. With Jing Dong. Industry co-PI: Stephanie Gravenor from Northwestern Memorial Hospital. (My part: $296,229.)

  • 2020-2023. National Science Foundation (NSF), CMMI 2006350 (PI). Queuing Systems with Dependencies: Theory and Applications. co-PI: Achal Bassamboo. $348,029

    I am a co-Investigator in an HHS-sponsored grant:

  • 2018-2021. Agency for Healthcare Research and Quality (AHRQ), Project Number 1R18HS025359-01A1. Enhancing Stroke Prehospital and Emergency Evaluation and Delivery (E-SPEED). PI: Shyam Prabhakaran.

  • Students' First Jobs

    • Chenguang (Allen) Wu: Assistant professor at the Department of Industrial Engineering and Decision Analytics, HKUST (co-advisor: Achal Bassamboo)

    • Lun Yu: Assitant professor at the Industrial Engineering Department, Tsinghua University (starting Fall 2022; co-advisor: Seyed Iravani)

    • Yue Hu Assistant professor at the Operations, Information & Technology Department, Stanford's Graduate School of Business (starting Fall 2023; co-advised with Jing Dong and Carri W. Chan)