Ibrahim, R. and W. Whitt. Real-Time Delay Estimation Based on Delay History.
Manufacturing and Service Operations Management, 11(3), 2009, pp 397-415.
[PDF]. Supplementary material: [PDF].
Ibrahim, R. and W. Whitt. Real-Time Delay Estimation in Overloaded Multiserver Queues with Abandonment.
Management Science, 55(10), 2009, pp.1729-1724.
[PDF]. Supplementary material: [PDF].
Ibrahim, R. and W. Whitt. Real-Time Delay Estimation Based on Delay History in Many-Server Service Systems with Time-Varying Arrivals.
Production and Operations Management, 20(5), 2011, pp. 654-667.
[PDF]. Supplementary material: [PDF].
Ibrahim, R. and W. Whitt. Wait-Time Predictors for Customer Service Systems with Time-Varying Demand and Capacity.
Operations Research, 59(5), 2011, pp. 1106-1118.
[PDF].
Ibrahim, R. and P. L'Ecuyer. Forecasting Call Center Arrivals: Fixed-Effects, Mixed-Effects, and Bivariate Models.
Manufacturing and Service Operations Management, 15(1), 2013, pp. 72-85.
[PDF].
Ibrahim, R., L'Ecuyer, P., Shen, H., and M. Thiongane. Inter-Dependent, Heterogeneous, and Time-Varying Service-Time Distributions in Call Centers. [PDF]. The European Journal of Operational Research, 250, 2016, pp. 480-492. Supplementary material: [PDF].
Ibrahim, R., Kucukyazici, B., Verter, V., Gendreau, M. and M. Bolstein. Designing Individualized Treatment: An Application to Anticoagulation Therapy.
[PDF]. Production and Operations Management, 25 (5), 2016, pp. 902-918. Technical appendix: [PDF]. Supplementary material: [PDF].
Ibrahim, R., Ye, H., L'Ecuyer, P. and H. Shen. Modeling and Forecasting Call Center Arrivals: A Literature Survey and a Case Study. The International Journal of Forecasting, 32(3), 2016, pp. 865-874.
[PDF].
Ibrahim, R., Armony, M., and A. Bassamboo. Does the Past Predict the Future? The Case of Delay Announcements in Service Systems. [PDF]. Management Science, 63(6), 2017, pp. 1762-1780. Supplementary material: [PDF].
Ibrahim, R. Managing Queueing Systems Where Capacity Is Random and Customers Are Impatient. Production and Operations Management, 27(2), 2018, pp. 207-383.
[PDF].
(Finalist in INFORMS JFIG paper competition, 2015.)
Ibrahim, R. Sharing Delay Information in Service Systems: A Literature Survey. Queueing Systems, 89(1-2), 2018, pp. 49-79. [PDF].
Ibrahim, R. and S-H Kim. Predicting Surgery Duration: Physician Input, Statistical Models, and Combined Models. [PDF]. Seoul Journal of Business, 25(2), 2019, pp. 1-33.
Dong, J. and R. Ibrahim. Flexible Workers or Full-Time Employees? On Staffing Service Systems with a Blended Workforce. [PDF]. Operations Research, 68(4), 2020, pp. 965-1284.
Bassamboo, A. and R. Ibrahim. A General Framework to Compare Announcement Accuracy: Static vs LES-based Announcement. [PDF]. Management Science, 67 (7), 2021,
pp . 3985-4642. Supplementary material: [PDF].
Ibrahim, R., Kim, S-H., and J. Tong. Eliciting Human Judgment for Prediction Algorithms [PDF]. Management Science, 67 (4), 2021, pp. 1993-2656.
Dong, J. and R. Ibrahim. On the SRPT Scheduling Discipline in Many-Server Queues with Impatient Customers. [PDF]. Management Science, 67(12), 2021, pp. 7291-7950.
Ibrahim, R. Personalized Scheduling in Service Systems. [PDF]. Queueing Systems: 100 Views on Queueing (SI), 100, 2022, pp. 445-447.
Momesso, T., B. Gokpinar, R. Ibrahim, and A. Boyle. The Effect of Removing the Four-Hour Access Standard in the ED:
A Retrospective Observational Study. [PDF]. Supplementary material: [PDF]. Emergency Medicine Journal, 40, 2023, pp. 630-635.
Rodriguez, A. E., Ibrahim, R. and D. Zhan. On Customer (Dis)honesty in Priority Queues:
The Role of Lying Aversion. [PDF]. Management Science, forthcoming.
(Second place in Behavioral OM best working paper, 2021.) (Finalist in IBM best student paper (A. Estrada), 2021.)
Referee Proceedings and Book Chapters
Ibrahim, R. and W. Whitt. Real-Time Delay Estimation in Call Centers.
Proceedings of the 2008 Winter Simulation Conference, 2008, pp. 2876-2883.
[PDF].
Ibrahim, R. and W. Whitt. Delay Predictors for Customer Service Systems with Time-Varying Parameters.
Proceedings of the 2010 Winter Simulation Conference, 2010, pp. 2375-2386.
[PDF].
Ibrahim, R., L'Ecuyer, P., Regnard, N., and H. Shen. On the Modeling and Forecasting of Call Center Arrivals.
Proceedings of the 2012 Winter Simulation Conference, 2012, pp. 23-35.
[PDF].
Ibrahim, R. On Queues with a Random Capacity: Some Theory, and an Application. In: Hu
M. (eds) Sharing Economy, Springer Series in Supply Chain Management, 6, 2019,
pp. 279-316
.[PDF].
Completed Drafts
Dong, J. and R. Ibrahim. Shortest-Job-First Scheduling in Many-Server Queues
with Impatient Customers and Noisy Service-Time
Estimates. [PDF].
Afeche, P., Hu, J., Ibrahim, R. and V. Sarhangian. The Effects of Information Granularity on
Abandonment and Congestion in Non-Stationary
Priority Queues. [PDF].
Tuncalp, F., Ibrahim, R., Kim, S-H., and J. Tong. When Should Doctors and Patients Use Shared
Decision-Making Under Bounded Rationality? [PDF].
Rodriguez, A. E., Ibrahim, R. and M. Kremer. Persuasive Communication in Social Service Operations [PDF].
Doctoral Thesis
Real-time delay prediction in customer service systems [PDF].