Wu Q., Xie N., Leus R. and Zheng S. A two-stage column-generation-based matheuristic for integrated scheduling in a cloud manufacturing environment. European Journal of Operational Research, to appear. (pdf) (DOI)
Moura P.F.S., Yaman H. and Leus R. On the connected (sub)partition polytope. Mathematical Programming, to appear. (pdf) (DOI)
Wang X., Zhou G., Leus R and Creemers S. A parallel computing approach for scheduling Markovian project networks to maximize the expected net present value. European Journal of Operational Research, 335(2), 393-408. (pdf) (DOI)
Chen X., Tang W., Leus R. and Zhu X. (2026). Scheduling passenger and freight co-modal transport for a high-speed rail reservation platform: a column-and-row generation-based modular framework. Transportation Research Part E, 214, number 105041. (pdf) (DOI)
Yang K., Song G., Wang R., Yang H. and Leus R. (2026). Perspective Benders decomposition with applications to fixed-charge nonlinear resource allocation. INFORMS Journal on Computing, 38(3), 691-1031. (pdf) (DOI)
Wang X., Han C. and Leus R. (2026). Scheduling multiple agile Earth observation satellites with multiple observations. Advances in Space Research, 77(11), 11184-11198. (pdf) (DOI, open access)
Han T., Wei Y., Leus R. and Xia Y. (2026). Integrated Optimization of Train Stop Planning, Train Timetabling, and Maintenance Planning for Railway Container System Under Passenger Transport Mode. Journal of Rail Transport Planning & Management, 38, 100580. (pdf) (DOI)
Long S., Dong Y., Li S., Lei J., Leus R. and Zhang J. (2026). Beyond single-source adversaries: Diversity-driven ensemble adversarial training for object detectors. Knowledge-Based Systems, 341, 115810. (pdf) (DOI)
Tao H., Song G., Leus R., Liang Z. and Jiang J. (2026). Flight test scheduling: A generic model, lower bounds, and iterated local search. European Journal of Operational Research, 328(1), 49-63. (pdf) (DOI)
Zhang D., Song G., Leus R. and Zhang L. (2026). Adjustable target-oriented robust optimization for inventory management. Naval Research Logistics, 73(2), 268-290. (pdf) (DOI) (e-companion)
Hu L., Zhang Y., Wen M., Leus R. and Zhang N. (2025). Robust parallel machine selection and scheduling with uncertain release times. European Journal of Operational Research, 327(3), 838-856. (pdf) (DOI)
Zhao B., Wang K., Wei W. and Leus R. (2025). The Dial-a-Ride problem with limited pickups per trip. European Journal of Operational Research, 327(3), 776-790. (pdf) (DOI)
Moura P.F.S., Leus R., and Yaman H. (2025). Compact formulations and valid inequalities for parallel machine scheduling with conflicts. European Journal of Operational Research, 325(3), 433-443. (pdf) (DOI)
Demeulemeester T., Goossens D., Hermans B. and Leus R. (2025). Fair integer programming under dichotomous and cardinal preferences. European Journal of Operational Research, 320(3), 465-478. (pdf) (DOI)
Muñoz-Díaz M.L., Escudero-Santana A., Lorenzo-Espejo A. and Leus R. (2025). Single station MILP scheduling in discrete and continuous time. Central European Journal of Operations Research, 33, 1213-1225. (pdf) (DOI, open access)
Kowalczyk D., Leus R., Hojny C. and Røpke S. (2024). A flow-based formulation for parallel machine scheduling using decision diagrams. INFORMS Journal on Computing, 36(6), 1696-1714. (pdf) (DOI)
Zhao Y., Zhou H. and Leus R. (2024). Decision timing, information inference, and information sharing: A robust supply chain game with two-way information asymmetry. Transportation Research Part E, 192, number 103807. (pdf) (DOI)
Yang F., Hermans B., Zufferey N. and Leus R. (2024). Sequential testing in batches with resource constraints. Expert Systems With Applications, 256, number 124858. (pdf) (DOI)
Rostami S., Creemers C. and Leus R. (2024). Maximizing the net present value of a project under uncertainty: Activity delays and dynamic policies. European Journal of Operational Research, 317(1), 16-24. (pdf) (DOI, open access)
Zhao B. and Leus R. (2024). An improved decomposition-based heuristic for truck platooning. Computers and Operations Research, 161, number 106439. (pdf) (DOI)
Morandi N., Leus R. and Yaman H. (2024). The Orienteering Problem with drones. Transportation Science, 58(1), 240-256. (pdf) (DOI)
Morandi N., Leus R., Matuschke J. and Yaman H. (2023). The TSP with drones: The benefits of retraversing the arcs. Transportation Science, 57(5), 1340-1358. (pdf) (DOI)
Demeulemeester T., Goossens D., Hermans B. and Leus R. (2023). A pessimist’s approach to one-sided matching. European Journal of Operational Research, 305(3), 1087-1099. (pdf) (DOI)
Hermans B., Leus R. and Van Looy B. (2023). Deciding on scheduling, secrecy, and patenting during the new product development process: the relevance of project planning models. Omega, 116, article number 102814. (pdf) (DOI)
Song G. and Leus R. (2022). Parallel machine scheduling under uncertainty: Models and exact algorithms. INFORMS Journal on Computing, 34(6), 3059-3079. (pdf) (DOI) (online supplement)
Zhao Y., Zhou H. and Leus R. (2022). Recovery from demand disruption: two-stage financing strategy for a capital-constrained supply chain under uncertainty. European Journal of Operational Research, 303(2), 699-718. (pdf) (DOI)
Yang F., Davari M., Wei W., Hermans B. and Leus R. (2022). Scheduling a single parallel-batching machine with non-identical job sizes and incompatible job families. European Journal of Operational Research, 303(2), 602-615. (pdf) (DOI)
Vié M.S., Zufferey N. and Leus R. (2022). Aircraft Landing Planning under Uncertain Conditions. Journal of Scheduling, 25, 203-228. (pdf) (DOI)
Morandi N., Leus R. and Yaman H. (2022). Exact algorithms for budgeted prize-collecting covering subgraph problems. Computers and Operations Research, 144, article number: 105798. (pdf) (DOI)
Agnetis A., Hermans B., Leus R. and Rostami S. (2022). Time-critical testing and search problems. European Journal of Operational Research, 296(2), 440-452. (pdf) (DOI)
Yan J., Song G., Leus R., Hou Z. and Zhang Z. (2022). Rolling weight-matching methods for the inter-satellite link assignment in global navigation satellite systems. GPS Solutions, 26(2), article number: 38. (pdf) (DOI)
Hermans B., Leus R. and Matuschke J. (2022). Exact and approximation algorithms for the expanding search problem. INFORMS Journal on Computing, 34(1), 281-296. (pdf) (DOI)
Yang F. and Leus R. (2021). Scheduling hybrid flow shops with time windows. Journal of Heuristics, 27, 133-158. (pdf) (DOI)
Song G., Kis T. and Leus R. (2021). Polyhedral results and branch-and-cut for the resource loading problem. INFORMS Journal on Computing, 33(1), 105-119. (pdf) (DOI) (instances)
Wang X., Song G., Leus R. and Han C. (2020). Robust Earth observation satellite scheduling with uncertainty of cloud coverage. IEEE Transactions on Aerospace and Electronic Systems, 56(3), 2450-2461. (pdf) (DOI)
Davari M., Ranjbar M., De Causmaecker P. and Leus R. (2020). Minimizing makespan on a single machine with release dates and inventory constraints. European Journal of Operational Research, 286(1), 115-128. (pdf) (DOI)
Du B., Zhou H. and Leus R. (2020). A two-stage robust model for a reliable p-center facility location problem. Applied Mathematical Modelling, 77(1), 99-114. (pdf) (DOI)
Hermans B., Hamers H., Leus R. and Lindelauf R. (2019). Timely exposure of a secret project: Which activities to monitor? Naval Research Logistics, 66(6), 451-468. (pdf) (DOI)
Rostami, S., Creemers, S. and Leus, R. (2019). Precedence theorems and dynamic programming for the single-machine weighted tardiness problem. European Journal of Operational Research, 272(1), 43-49. (pdf) (DOI)
Rostami, S., Creemers, S., Wei, W. and Leus, R. (2019). Sequential testing of n-out-of-n systems: Precedence theorems and exact methods. European Journal of Operational Research, 274(3), 876-885. (pdf) (DOI)
Kowalczyk, D. and Leus, R. (2018). A branch-and-price algorithm for parallel machine scheduling using ZDDs and generic branching. INFORMS Journal on Computing, 30(4), 625-782. (pdf) (DOI) (online supplement)
Song, G., Kowalczyk, D. and Leus, R. (2018). The robust machine availability problem - bin packing under uncertainty. IISE Transactions, 50(11), 997-1012. (pdf) (DOI) (instances)
Rostami, S., Creemers, S. and Leus, R. (2018). New strategies for stochastic resource-constrained project scheduling. Journal of Scheduling, 21(3), 349-365. (pdf) (DOI)
Hermans, B. and Leus, R. (2018). Scheduling Markovian PERT networks to maximize the net present value: New results. Operations Research Letters, 46, 240-244. (pdf) (DOI)
Melchiors, P., Leus, R., Creemers, S. and Kolisch, R. (2018). Dynamic Order Acceptance and Capacity Planning in a Stochastic Multi-Project Environment with a Bottleneck Resource. International Journal of Production Research, 56(1-2), 459-475. (pdf) (DOI)
Wei, W.C., Li, H.B. and Leus, R. (2017). Test sequencing for sequential system diagnosis with precedence constraints and imperfect tests. Decision Support Systems, 103, 104-116. (pdf) (DOI)
Kowalczyk, D. and Leus, R. (2017). An exact algorithm for parallel machine scheduling with conflicts. Journal of Scheduling, 20, 355–372. (pdf) (DOI)
Wei W., Coolen K., Talla Nobibon F. and Leus R. (2017). Minimum-cost diagnostic strategies for k-out-of-n systems with imperfect tests. Discrete Applied Mathematics, 222, 185-196. (pdf) (DOI)
Davari, M., Demeulemeester, E., Leus, R. and Talla Nobibon, F. (2016). Exact algorithms for single-machine scheduling with time windows and precedence constraints. Journal of Scheduling, 19, 309–334. (pdf) (DOI) (instances)
Xiong, J., Leus, R., Yang, Z. and Abbass, H.A. (2016). Evolutionary Multi-Objective Resource Allocation and Scheduling in the Chinese Navigation Satellite System Project. European Journal of Operational Research, 251(2), 662-675. (pdf) (DOI)
Zhu, H., Leus, R., and Zhou, H. (2016). New results on the coordination of transportation and batching scheduling. Applied Mathematical Modelling, 40, 4016-4022. (pdf) (DOI)
Berghman, L. and Leus, R. (2015). Practical solutions for a dock assignment problem with trailer transportation. European Journal of Operational Research, 246(3), 787-799. (pdf) (DOI) (instances)
Talla Nobibon, F., Leus, R., Nip, K., and Wang, Z. (2015). Resource loading with time windows. European Journal of Operational Research, 244, 404-416. (pdf) (DOI)
Jabali, O., Leus, R., Van Woensel, T. and de Kok, T. (2015). Self-Imposed Time Windows in Vehicle Routing Problems. OR Spectrum, 37(2), 331-352. (pdf) (DOI)
Huysmans, M., Coolen, K., Talla Nobibon, F. and Leus, R. (2015). A fast greedy heuristic for scheduling modular projects. Journal of Heuristics, 21(1), 47-72. (pdf) (DOI)
Nip, K., Wang, Z., Talla Nobibon, F. and Leus, R. (2015). A combination of flow shop scheduling and the shortest path problem. Journal of Combinatorial Optimization, 29(1), 36-52. (pdf) (DOI)
Creemers, S., De Reyck, B. and Leus, R. (2015). Project planning with alternative technologies in uncertain environments. European Journal of Operational Research, 242(2), 465-476. (pdf) (DOI)
Talla Nobibon, F. and Leus, R. (2014). Complexity results and exact algorithms for robust knapsack problems. Journal of Optimization Theory and Applications, 161(2), 533-552. (pdf) (DOI) ((more elaborate) working paper) (instances)
Talla Nobibon, F. and Leus, R. (2014). Robust maximum weighted independent-set problems on interval graphs. Optimization Letters, 8(1), 227-235. (pdf) (DOI)
Coolen, K., Wei, W., Talla Nobibon, F. and Leus, R. (2014). Scheduling modular projects on a bottleneck resource. Journal of Scheduling, 17(1), 67-85. (pdf) (DOI) (instances)
Berghman, L., Leus, R. and Spieksma, F.C.R. (2014). Optimal solutions for a dock assignment problem with trailer transportation. Annals of Operations Research, 213(1), 3-25. (pdf) ((more elaborate) working paper) (DOI) (instances)
Delanote, S., Leus, R. and Talla Nobibon, F. (2013). Optimization of the annual planning of targeted offers in direct marketing. Journal of the Operational Research Society, 64(12), 1770-1779. (pdf) (DOI)
Talla Nobibon, F., Coolen, K. and Leus, R. (2013). A Note on `Discrete Sequential Search with Group Activities'. Decision Sciences, 44(2), 395-401. (pdf) (DOI)
In this paper, we provide a counterexample to the claim that a particular combinatorial problem could be solved by means of one particular linear-programming formulation. In fact, a stronger result holds, namely that the problem is NP-hard. For a proof and discussion, see the working paper.
Artigues, C., Leus, R. and Talla Nobibon, F. (2013). Robust optimization for resource-constrained project scheduling with uncertain activity durations. Flexible Services and Manufacturing, 25, 175-205. (pdf) (DOI)
Wei, W., Coolen, K. and Leus, R. (2013). Sequential testing policies for complex systems under precedence constraints. Expert Systems with Applications, 40, 611-620. (pdf) (DOI) (instances)
Lambrecht, M., Creemers, S., Boute, R. and Leus, R. (2012). Extending the production dice game. International Journal of Operations and Production Management, 32(12), 1460-1472. (pdf) (DOI) (website)
Talla Nobibon, F., Hurkens, C., Leus, R. and Spieksma, F.C.R. (2012). Coloring graphs using two colors while avoiding monochromatic cycles. INFORMS Journal on Computing, 24, 485-499. (pdf) (supplement) (DOI) (instances)
Ranjbar, M., Davari, M. and Leus, R. (2012). Two branch-and-bound algorithms for the robust parallel machine scheduling problem. Computers & Operations Research, 39, 1652-1660. (pdf) (DOI)
Leus, R. (2011). Resource allocation by means of project networks: dominance results. Networks, 58(1), 50-58. (pdf) (DOI)
Leus, R. (2011). Resource allocation by means of project networks: complexity results. Networks, 58(1), 59-67. (pdf) (DOI)
Ashtiani, B., Leus, R. and Aryanezhad, M.-B. (2011). New competitive results for the stochastic resource-constrained project scheduling problem: exploring the benefits of pre-processing. Journal of Scheduling, 14(2), 157-171. (pdf) (DOI)
Talla Nobibon, F., Leus, R. and Spieksma, F.C.R. (2011). Optimization models for targeted offers in direct marketing: exact and heuristic algorithms. European Journal of Operational Research, 210, 670-683. (pdf) (DOI) (instances)
Talla Nobibon, F. and Leus, R. (2011). Exact algorithms for a generalization of the order acceptance and scheduling problem in a single-machine environment. Computers & Operations Research, 38, 367-378. (pdf) (DOI) (instances)
Herbots, J., Herroelen, W. and Leus, R. (2010). Single-pass and approximate dynamic-programming algorithms for order acceptance and capacity planning. Journal of Heuristics, 16, 189-209. (pdf) (DOI)
Creemers, S., Leus, R. and Lambrecht, M. (2010). Scheduling Markovian PERT networks to maximize the net present value. Operations Research Letters, 38, 51-56. (pdf) (DOI)
Ballestín, F. and Leus, R. (2009). Resource-constrained project scheduling for timely project completion with stochastic activity durations. Production and Operations Management, 18(4), 459-474. (pdf) (DOI)
Berghman, L., Goossens, D. and Leus, R. (2009). Efficient solutions for Mastermind using genetic algorithms. Computers & Operations Research, 36, 1880-1885. (pdf) (DOI) (accompanying files)
De Reyck, B., Grushka-Cockayne, Y. and Leus, R. (2007). A new challenge in project scheduling: the incorporation of activity failures. Review of Business and Economics, LII(3), 411-434. (pdf) (journal formerly entitled "Tijdschrift voor Economie en Management")
Herbots, J., Herroelen, W. and Leus, R. (2007). Dynamic order acceptance and capacity planning on a single bottleneck resource. Naval Research Logistics, 54(8), 874-889. (pdf) (DOI)
Leus, R. and Herroelen, W. (2007). Scheduling for stability in single-machine production systems. Journal of Scheduling, 10, 223-235. (pdf) (DOI)
Hans, E., Herroelen, W., Leus, R. and Wullink, G. (2007). A hierarchical approach to multi-project planning under uncertainty. Omega-International Journal of Management Science, 35, 563-577. (pdf) (DOI)
Van de Vonder, S., Demeulemeester, E., Herroelen, W. and Leus, R. (2006). The trade-off between stability and makespan in resource-constrained project scheduling. International Journal of Production Research, 44(2), 215–236. (pdf) (DOI)
Debels, D., De Reyck, B., Leus, R. and Vanhoucke, M. (2006). A hybrid scatter search / electromagnetism meta-heuristic for project scheduling. European Journal of Operational Research, 169, 638-653. (pdf) (DOI)
Van de Vonder, S., Demeulemeester, E., Herroelen, W. and Leus, R. (2005). The use of buffers in project management: the trade-off between stability and makespan. International Journal of Production Economics, 97(2), 227-240. (pdf) (DOI)
Herroelen, W. and Leus, R. (2005). Project Scheduling Under Uncertainty: Survey and Research Potentials. European Journal of Operational Research, 165(2), 289-306. (pdf) (DOI)
Herroelen, W. and Leus, R. (2005). Identification and illumination of popular misconceptions about project scheduling and time buffering in a resource-constrained environment. Journal of the Operational Research Society, 56, 102-109. (pdf) (DOI)
Leus, R. and Herroelen, W. (2005). The complexity of machine scheduling for stability with a single disrupted job. Operations Research Letters, 33, 151-156. (pdf) (DOI)
Leus, R. (2004). The generation of stable project plans. 4OR, the Quarterly Journal of the Belgian, French and Italian Operations Research Societies, 2(3), 251-254. (pdf) (DOI)
Leus, R. and Herroelen, W. (2004). Stability and resource allocation in project planning. IIE Transactions, 36(7), 667-682. (pdf) (DOI)
Herroelen, W. and Leus, R. (2004). The construction of stable project baseline schedules. European Journal of Operational Research, 156(3), 550-565. (pdf) (DOI)
Herroelen, W. and Leus, R. (2004). Robust and reactive project scheduling: a review and classification of procedures. International Journal of Production Research, 42(8), 1599-1620. (pdf) (DOI)
Elmaghraby, S.E.E., Herroelen, W.S. and Leus, R. (2003). Note on the paper Resource-constrained project management using enhanced theory of constraint. International Journal of Project Management, 21, 301-305. (pdf) (DOI)
Leus, R. (2003). The generation of stable project plans. Complexity and exact algorithms. PhD-thesis, Department of applied economics, Katholieke Universiteit Leuven.
All chapters of the thesis have been published as journal articles, some of which have been considerably updated compared to the thesis version. Therefore, I recommend reading the journal versions rather than the thesis.
Leus, R. (1998). Het opsporen van outliers in multivariate gegevens. Master's thesis Business Engineering ("Handelsingenieur"), Department of applied economics, Katholieke Universiteit Leuven.