ORAHS International Seminar Series

April 29th 2025, 16:00-17:00 CET - Prof. Henrik Andersson (NTNU, Norway) - Daily Surgical Case Scheduling with Upstream and Downstream Units

Title Daily Surgical Case Scheduling with Upstream and Downstream Units.

Abstract On the day of surgery, patients require multiple activities across different units before and after their surgical procedures, referred to as Upstream and Downstream Units (UDUs). We present the Surgical Case Scheduling Problem with Up- and Downstream Units (SCSPUDU), a problem that integrates UDUs in the daily surgical planning.

We have worked with Oslo University Hospital (OUS) and analyze the activities and associated resources along the surgical patient flows at the hospital. Currently, schedules are developed in a decentralized manner across surgical specialties, which can lead to delays and cancellations when schedules misalign. Addressing these challenges in daily scheduling decisions is essential for optimizing patient care, supporting staff well-being, and ensuring the efficient use of financial resources. To enhance coordination between units and reduce delays and cancellations at OUS, we explore the effect of integrating UDUs into their daily surgery scheduling, leading to the SCSPUDU.

Bio Henrik Andersson is a professor in Optimization at the Norwegian University of Science and Technology (NTNU). In 2006, he defended his doctoral thesis in Infra Informatics, entitled “Coordinated routing – applications in location and inventory management”. Three different applications within waste management, pulp distribution, and school relocation were analyzed. He joined NTNU in 2007 as a postdoctoral fellow and is since 2014 full professor.

Andersson has a diverse research background and has worked within maritime and road-based transportation, micromobility, emergency response, and healthcare among other areas. Within healthcare he has for example worked on rostering of nurses and surgeons focusing on cyclic scheduling, reactive/proactive strategies and integrating master surgery and outpatient clinic scheduling. He has collaborated closely with St Olavs hospital in Trondheim where he also has had a position as Researcher working with nurse rostering.

Registration You can register here for the upcoming seminar on April 29th 2025.

MaY 27th 2025, 16:00-17:00 CET - Dr. Marta Cildoz and Prof. Fermin Mallor (Public University of Navarre, Spain) - MAKE AN IMPACT: ENGAGING HOSPITAL MANAGERS TO MAKE DECISIONS SUPPORTED BY SIMULATION/DIGITAL TWIN MODELS

Title Make and impact: Engaging hospital managers to make decisions supported by simulation/digital twin models.

Abstract Building strong collaborations between research teams and healthcare decision-makers is key to driving meaningful change in hospital management. This talk will showcase how our research group has established a stable partnership with the regional health administration and the management of the main public hospital in Navarra, Spain, ensuring that our proposed solutions are either directly implemented or used to support strategic and tactical decision-making.

We will explore real-world healthcare challenges we have tackled using simulation-based models, including their evolution towards digital twins designed for tactical and operational management. A key focus will be on our ongoing work to reduce waiting times for specialized medical care—particularly in traumatology—where our findings have already justified significant structural changes in patient flow, IT systems, and healthcare management. Along the way, we will also highlight previous projects on optimizing emergency department patient flow, ICU capacity planning, and forecasting needs during the COVID-19 pandemic.

This presentation aims to inspire researchers to engage with healthcare stakeholders and leverage modeling techniques to create a real impact on decision-making.

Bio Marta Cildoz is an Assistant Professor in the Department of Statistics, Informatics, and Mathematics at the Public University of Navarra (UPNA), and Fermín Mallor is a Full Professor in the same department. Both are members of the q-UPHS research group (https://www.unavarra.es/quphs), which focuses on the application of operations research techniques to healthcare management.

Their research integrates simulation, optimization, and data-driven analytics to improve decision-making in healthcare, with a particular emphasis on patient flow management, resource allocation, and workforce scheduling. They have collaborated with institutions such as the Government of Navarra’s Health Department and the University Hospital of Navarra, developing practical solutions that support strategic and operational decision-making. Their work includes the development of digital twins and simulation models to optimize healthcare services, including ICU bed management, emergency department planning and operation, and medical staff scheduling.

They have participated in multiple research projects, funded by national and European programs, and have published extensively in high-impact journals. Their research not only contributes to theoretical advancements in healthcare operations research but also has a tangible impact on real-world healthcare management and policy.

Registration You can register here for the upcoming seminar on May 27th 2025.

Recordings of our previous seminar talks are available below.

• March 25th 2025: Prof. Christina Büsing, RWTH Aachen, Germany. Fair planning of out-of-hours service for pharmacies. The recording of the talk will be uploaded soon.
• February 25th 2025: Prof. Hari Balasubramanian, University of Massachusetts, Amherst, USA. Identifying Associations Between Diseases Using Association Rule Mining and Clustering Methods. The recording of the talk can be found here.
• January 28th 2025: Dr. Harwin de Vries, Rotterdam School of Management, Netherlands. Enhancing Access to Family Planning Services: Challenges and Opportunities for OR. The recording of the talk can be found here.
• November 26th 2024: Prof. Erik Demeulemeester, KU Leuven, Belgium. How can the partitioning of elective surgeries benefit the inpatient operating theater? The recording of the talk can be found here.
• October 29th 2024: Prof. Peter Vanberkel, Dalhousie University, Canada. Using Machine Learning to Develop Guidelines for Identifying Patients Who May Leave an Emergency Department Without Being Seen. The recording of the talk can be found here.
• September 24th 2024: Prof. Dimitris Bertsimas, Massachusetts Institute of Technology, USA. The R.O.A.D. to precision medicine. The recording of the talk can be found here.
• June 25th 2024: Dr. Derya Demirtas, University of Twente, NL. Unlocking the Value of Extensive Data: Estimating spatial cardiac arrest risk to guide resource allocation decisions. The recording of the talk can be found here.
• May 28th 2024: Prof. Dionne Aleman, University of Toronto, Canada. Pandemic planning from A (agent-based simulation) to V (vaccine prioritization). The recording of the talk can be found here.
• April 30th 2024: Prof. Mónica Oliveira, University of Lisbon, Portugal. Advancing collaborative value modeling in health settings: From applications to novel tools. The recording of the talk can be found here.
• March 19th 2024: Dr. Ana María Anaya-Arenas, Université du Québec à Montréal, Canada. The Biomedical Sample Transportation Problem: routing commodities with very short lifespan.
• February 27th 2024: Prof. Christine Currie, University of Southampton, UK. A Generalisable Digital Twin Simulation Model of an Emergency Department. The recording of the talk can be found here.
• January 30th 2024: Prof. Vedat Verter, Queens University, Canada. Nurse Workload Balancing Using Real-Time Location Data. The recording of the talk can be requested via email.
• November 28th 2023: Dr. Melanie Reuter, University of Twente, NL. SPELL: Supporting emergency services with OR- and AI-based approaches.
• October 17th 2023: Prof. Nadia Lahrichi, Polytechnique Montreal, Canada. Integrating bed use and patient selection to the master surgical planning in the OR. The recording of the talk can be found here.
• September 26th 2023: Prof.Em. Warren Powell, Princeton University, USA. A Universal Framework for Sequential Decision Problems in Health Applications. The recording of the talk can be found here.
• June 27th 2023: Dr. Ana Viana, Polytechnic of Porto, Portugal. Kidney Exchange Programmes: a guided tour from 2004 to 2023. The recording of the talk can be found here, and the corresponding slides here.
• May 30th 2023: Prof. Brian Denton, University of Michigan, MI, USA. Predictive and Prescriptive Models for Early Detection of Prostate Cancer. The recording of the talk can be found here.
• April 25th 2023: Dr. Gréanne Leeftink, University of Twente, NL. Capacity sharing in neonatal care networks. The recording of the talk can be found here.
• March 28th 2023: Prof. Lerzan Örmeci, Koç University, Turkey. Appointment Scheduling with Patient Preferences. The recording of the talk can be found here.
• February 28th 2023: Prof. Jens Brunner, University of Augsburg, Germany. Resident scheduling in teaching hospitals with the use of quantitative methods. The recording of the talk can be found here.
• January 31st 2023: Prof. Retsef Levi, MIT, USA. Analytics Driven Innovation in Health Systems. The recording of the talk can be found here.
• December 6th 2022: Prof. Richard Boucherie, University of Twente, NL. Dynamic assignment of capacity and fair balancing of COVID-19 patients over hospitals. The recording of the talk can be found here.
• November 11th 2022: Prof. Margaret Brandeau, Stanford University, USA. Replacing Complex Models for Health Decision Making with Metamodels: Three Examples. The recording of the talk can be found here.
• October 4th 2022 (joint seminar with WORMS): Prof. Sonya Crowe and Dr. Zella King, University College London, UK. Using OR to make real-time aggregated predictions of hospital admission for emergency patients. The recording of the talk can be found here.
• June 28th 2022: Prof. Paul Harper and Michalis Panayides, Cardiff University, UK. Modelling Healthcare Behaviours: A Game Theoretic Model Between Emergency Departments and Emergency Medical Services Queueing Systems. The recording of the talk can be found here.
• May 31st 2022: Prof. Stefan Nickel, Karlsruhe Institute of Technology, Germany. Health Care Logistics in EMS: A real world case combining Analytics, Simulation and Optimization. The recording of the talk can be found here.

The ORAHS international seminar series is organized by Amin Asadi, Aleida Braaksma, Derya Demirtas, Daniela Guericke, Gréanne Leeftink, Janusz Meylahn, Sebastian Rachuba, and Anne Zander of the CHOIR research center of the University of Twente (The Netherlands). For questions and inquiries feel free to reach out to us via email.

The ORAHS international seminar series is supported by its advisory board, consisting of Richard Boucherie (University of Twente, The Netherlands), and Erwin Hans (University of Twente, the Netherlands), and the ORAHS board.

The ORAHS international seminar series is a EURO Online Seminar Series (EURO OSS), economically supported by EURO.