Research pages for Armann Ingolfsson: Publications | Software | Data


Last updated 13 June 2020.


Rastpour, A., Kolfal, B., & Ingolfsson, A. (2020). Modeling Red and Yellow Alert durations for ambulance systems. Production and Operations Management. [Online supplement].

Samiedaluie, S., Tilson, A. & Ingolfsson, A. (2020). Models of the Impact of triage nurse standing orders on emergency department length of stay. [Submitted, last revision May 2020.]


Delasay, M., Ingolfsson, A., Kolfal, B., & Schultz, K. (2019). Load effect on service times. European Journal of Operational Research 279(3) 673–686.

Ingolfsson., A, Almehdawe, E., Pedram, A., & Tran, M. (2019). Comparison of fluid approximations for service systems with state-dependent service rates and return probabilities. European Journal of Operational Research 283(2) 562–575.


Rewa, O. G., Stelfox, H. T., Ingolfsson, A., Zygun, D. A., Featherstone, R., Opgenorth, D., & Bagshaw, S. M. (2018). Indicators of intensive care unit capacity strain: A systematic review. Critical Care, 22 86. doi: 10.1186/s13054-018-1975-3


Campello, F., Ingolfsson, A., & Shumsky, R. (2017). Queueing models of case managers. Management Science, 63(3) 882–900. doi:10.1287/mnsc.2015.2368 [Online supplement]


Delasay, M., Ingolfsson, A., & Kolfal, B. (2016). Modeling load and overwork effects in queueing systems with adaptive service rates. Operations Research 64(4) 867–885. doi:10.1287/opre.2016.1499 [Online supplement]

Delasay, M., Ingolfsson, A., & Schultz, K. (2016). Inventory is people: How load affects service times in emergency response. In Gavirneni, S. (Ed.). Cross-Functional Inventory Research. World Scientific.


Abolfazl Soltani, S., Ingolfsson, A., Zygun, D. A., Stelfox, H. T., Hartling, L., Featherstone, R., Opgenorth, D., & Bagshaw, S. M. (2015). Quality and performance measures of strain on intensive care capacity: A protocol for a systematic review. Systematic Reviews 4: 158. doi:10.1186/s13643-015-0145-9


Haerian, L., Haight, D., Ingolfsson, A., Salama, M., & Stanton., M. (2014). Scheduling and routing ambulances that provide inter-facility patient transfers. [Submitted, last revision August 2014.]

Holmes, G., Ingolfsson, A., Patterson, R., & Rolland, E. (2014). Model specification and data aggregation for emergency services facility location. [Supplement] [Submitted, last revision August 2014.]


Alanis, R., Ingolfsson, A., & Kolfal, B. (2013). A Markov chain model for an EMS system with repositioning. Production and Operations Management 22(1) 216–231. doi: 10.1111/j.1937-5956.2012.01362.x

Ta. C.H., Ingolfsson, A., & Doucette, J. (2013). A linear model for surface mining haul truck allocation incorporating shovel idle probabilities. European Journal of Operational Research 231(3) 770–778. doi:10.1016/j.ejor.2013.06.016


Ingolfsson, A. (2012). EMS Planning and Management. In Operations Research and Health Care Policy (pp. 105–128). Springer New York. doi 10.1007/978-1-4614-6507-2_6

Delasay, M., Kolfal, B., & Ingolfsson, A. (2012). Maximizing throughput in finite-source parallel queue systems. European Journal of Operational Research 217(3) 554–559. doi:10.1016/j.ejor.2011.09.041

Ingolfsson, A. & Tang, L. (2012). Efficient and reliable computation of birth-death process performance measures [Supplement] INFORMS Journal on Computing, 24(1) 29–41. doi: 10.1287/ijoc.1100.0435


Campello, F. & Ingolfsson, A. (2011). Exact necessary staffing requirements based on stochastic comparisons with infinite-server models [Submitted, last revised January 2011].

Caron, R. J., Ingolfsson, A., & Quan, V. (2011). The Canadian Operational Research Society / Société Canadienne de Recherche Opérationelle. Wiley Encyclopedia of Operations Research and Management Science. doi: 10.1002/9780470400531.eorms1049

Sadeghi, N., Robinson Fayek, A., & Ingolfsson, A. (2011). Simulation-based approach for estimating project completion time of stochastic resource-constrained project networks. ASCE Journal of Computing in Civil Engineering 26(4) 558–560. doi: 10.1061/(ASCE)CP.1943-5487.0000165


Budge, S., Ingolfsson, A., & Zerom, D. (2010). Empirical analysis of ambulance travel times: The case of Calgary Emergency Medical Services. Management Science 56(4) 716–723. 10.1287/mnsc.1090.1142

Castillo, I., Ingolfsson, A., & Sim, T. (2010). Socially optimal location of facilities with fixed servers, stochastic demand, and congestion. Production and Operations Management 18(6) 721–736 [Erratum.] doi: 10.1111/j.1937-5956.2009.01034.x

Day, T. E., Li, M. W., Ingolfsson, A., & Ravi, N. (2010). The use of queueing and simulative analyses to improve an overwhelmed pharmacy call center. Journal of Pharmacy Practice 23(5) 492–495. doi: 10.1177/0897190009358772

Erdogan, G., Erkut, E., Ingolfsson, A., & Laporte, G. (2010). Scheduling ambulance crews for maximum coverage. Journal of the Operational Research Society 61(4) 543–550. doi:10.1057/jors.2008.163

Ingolfsson, A. 2010. Ice Hockey. Wiley Encyclopedia of Operations Research and Management Science. doi: 10.1002/9780470400531.eorms0392

Ingolfsson, A., Campello, F., Wu, X., & Cabral, E. (2010). Combining integer programming and the randomization method to schedule employees. [Supplement:Additional computational results] European Journal of Operational Research 202(1) 153–163. doi:10.1016/j.ejor.2009.04.026


Budge, S., Ingolfsson, A., & Erkut, E. (2009). Technical note—Approximating vehicle dispatch probabilities for emergency service systems with location-specific service times and multiple units per location. Operations Research 57(1) 251–255 [supplement] doi: 10.1287/opre.1080.0591

Erkut, E., Ingolfsson, A., Sim, T., & Erdogan, G. (2009). Computational comparison of five maximal covering models for locating ambulances. Geographical Analysis 41(1) 43–65. doi: 10.1111/j.1538-4632.2009.00747.x


Budge, S., Ingolfsson, A., & Erkut, E. (2008). Optimal ambulance location with random delays and travel times. Health Care Management Science 11(3) 262–274. doi: 10.1007/s10729-007-9048-1

Erkut, E, Ingolfsson, A., & Budge, S. (2008). Maximum availability/reliability models for selecting ambulance station and vehicle locations: a critique [Unpublished manuscript]

Erkut, E., Ingolfsson, A., & Erdogan, G. (2008). Ambulance deployment for maximum survival. Naval Research Logistics 55(1) 42–58. doi: 10.1002/nav.20267

Grassmann, W. K., Puterman, M. L, L'Ecuyer, P., & Ingolfsson, A. (2008). Four Canadian contributions to stochastic modeling. INFOR 46(1) 3–14. doi: 10.3138/infor.46.1.3


Channouf, N., L'Ecuyer, P., Ingolfsson, A., & Avramidis, A. N. (2007). The application of forecasting techniques to modeling emergency medical system calls in Calgary, Alberta. Health Care Management Science 10(1) 25–45. doi: 10.1007/s10729-006-9006-3

Deslauriers, A., L'Ecuyer, P., Pichitlamken, J., Ingolfsson, A., & Avramidis, A. N. (2007). Markov chain models of a telephone call center with call blending. Computers & Operations Research 34(6) 1616–1645. doi:10.1016/j.cor.2005.06.019

Ingolfsson, A., Akhmetshina, E., Budge, S., Li, Y., & Wu, X. (2007). A survey and experimental comparison of service level approximation methods for non-stationary M/M/s queueing systems. INFORMS Journal of Computing 19(2) 201–214. doi: 10.1287/ijoc.1050.0157


Erkut, E., & Ingolfsson, A. (2005). Transport risk models for hazardous materials: Revisited. Operations Research Letters 33(1) 81–89. doi:10.1016/j.orl.2004.02.006

Ingolfsson, A. (2005). Modeling the M(t)/M/s(t) queue with an exhaustive discipline. [Unpublished manuscript.]


Ingolfsson, A. (2004). Simulating NHL games to motivate student interest in OR/MS. INFORMS Transactions on Education 5(1) 10.1287/ited.5.1.37 .


Ingolfsson, A., Erkut, E., & Budge, S. (2003). Simulation of single start station for Edmonton EMS. Journal of the Operational Research Society 54(7) 736–746. doi:10.1057/palgrave.jors.2601574

Litchfield, J., Ingolfsson, A., & Cheng, J. (2003). Rostering for a restaurant. INFOR 41(3) 287–300.


Ingolfsson, A., & Grossman, Jr, T. A. (2002). Graphical spreadsheet simulation of queues. INFORMS Transactions on Education 2(2) 27–39 doi: 10.1287/ited.2.2.27 .

Ingolfsson, A., Haque, M. A. , & Umnikov, A. (2002). Accounting for time-varying queueing effects in tour scheduling. European Journal of Operational Research 139(3) 585–597. doi:10.1016/S0377-2217(01)00169-2


Erkut, E., & Ingolfsson, A. (2000). Catastrophe avoidance models for hazardous materials route planning. Transportation Science 34(2) 165–179. doi: 10.1287/trsc.

Erkut, E., & Ingolfsson, A. (2000). Let's put the squares in least-squares. INFORMS Transactions on Education 1(1) 47–50 doi: 10.1287/ited.1.1.47 .

Grossman, Jr., T. A., & Ingolfsson, A. (2000). Graphical spreadsheet simulation of queues. Decision Sciences Institute Annual Meeting, Innovative Approaches for Teaching with Spreadsheets Mini-Conference, Orlando, Florida, November.


Ingolfsson A., & Zalkind, D. (1999). The teachers' forum: Two looks at the spinner experiment. Interfaces 29(6) 112–122. doi: 10.1287/inte.29.6.112


Sachs, E., Hu, A., & Ingolfsson, A. (1995). Run by run process control: Combining SPC and feedback control. IEEE Transactions on Semiconductor Manufacturing 8(1) 26–43. doi: 10.1109/66.350755


Ingolfsson, A., & Sachs, E. (1993). Stability and sensitivity of an EWMA controller. Journal of Quality Technology 25(4) 271–287.


Hu, A., Sachs, E., Ingolfsson, A., & Langer, P. (1992, June). Run-by-run process control: performance benchmarks. In Semiconductor Manufacturing Science Symposium, 1992. ISMSS 1992., IEEE/SEMI International (pp. 73–78). IEEE. 10.1109/ISMSS.1992.197640


Sachs, E., Hu, A., Ingolfsson, A., & Langer, P. H. (1991, October). Modeling and control of an epitaxial silicon deposition process with step disturbances. In Advanced Semiconductor Manufacturing Conference and Workshop, 1991. ASMC 91 Proceedings. IEEE/SEMI 1991 (pp. 104–107). IEEE. doi: 10.1109/ASMC.1991.167393


Sachs, E., Ingolfsson, A., & Ha, S. (1990, September). Tuning a process while performing SPC: an approach based on the sequential design of experiments. In Advanced Semiconductor Manufacturing Conference and Workshop, 1990. ASMC 90 Proceedings. IEEE/SEMI 1990 (pp. 126–130). IEEE. doi: 10.1109/ASMC.1990.111236

Sachs, E., Ingolfsson, A., & Ha, S. (1990, October). Run by run process control. In Electronic Manufacturing Technology Symposium, 1990 Proceedings, Competitive Manufacturing for the Next Decade. IEMT Symposium, Ninth IEEE/CHMT International (p. 184). IEEE. doi: 10.1109/IEMT9.1990.115003