As part of the OPTIMA international research exchange program, I undertook a one-month visit to the University of Modena and Reggio Emilia (UNIMORE) in Italy, from 2 September to 2 October 2025. The exchange was hosted by Professor Manuel Iori, a leading researcher in operations research and combinatorial optimisation, and Dr. Giulia Caselli, his postdoctoral researcher. This visit provided an invaluable opportunity to strengthen my ongoing PhD research in stochastic optimisation for operating room (OR) scheduling, develop new collaborations, and experience working within a vibrant European research environment.

The primary aim of my exchange was to extend and refine my existing surgery scheduling model by incorporating new decision-making layers related to primary and backup surgeon assignment. These additions aimed to capture a more realistic representation of the staffing structure in hospital operating rooms, where unforeseen emergencies and surgeon unavailability can significantly disrupt schedules. Another important component of the visit was to explore methodological advancements in model-solving techniques, particularly shifting from a sample average approximation (SAA) approach to an L-shaped decomposition algorithm for large-scale stochastic problems. This methodological improvement enables more efficient computation and provides deeper insights into the structure of uncertainty within surgical scheduling systems.

During the visit, I worked closely with Professor Iori and Dr. Caselli to formulate the new model structure and implement the additional constraints related to surgeon assignment. We also expanded the planning horizon from one week to one month, allowing for the evaluation of resource allocation and performance indicators over longer periods. This adjustment helps better capture variability in emergency arrivals and elective surgery demand across weeks, reflecting more realistic hospital operations. Together, these model extensions represent a significant step forward in bridging the gap between tactical and operational planning in surgery scheduling.

In collaboration with my hosts, I also explored the application of L-shaped decomposition (Benders decomposition) to solve the model more efficiently. The L-shaped method decomposes the large-scale stochastic problem into a master problem and multiple scenario- based subproblems, significantly reducing computational time while maintaining optimality. This approach not only improves scalability for larger hospitals but also enhances the interpretability of the stochastic solution. The implementation of this algorithm was successfully tested on synthetic hospital data, producing promising preliminary results that we plan to refine and publish in a joint academic paper.

Throughout the exchange, I had the opportunity to engage with members of the Operations Research group at UNIMORE, participating in discussions about optimisation methods, and recent advances in mixed-integer programming. These interactions broadened my perspective on the practical applications of optimisation in different sectors, including manufacturing, transportation, and healthcare. The academic environment at UNIMORE was highly collaborative, and the exchange of ideas during informal meetings and discussions played a crucial role in shaping the direction of our ongoing research.

Beyond research collaboration, the exchange provided valuable professional and cultural experiences. Living in Reggio Emilia allowed me to experience Italian academic life and interact with international researchers in operations research. I had insightful discussions with other PhD students and postdoctoral fellows, sharing experiences and exploring future collaborations. The warm and supportive atmosphere of the host department made the experience both academically stimulating and personally rewarding.

On the final day of my visit, I delivered a seminar presentation summarising my research achievements and the progress made during the exchange. The seminar, attended by faculty members, researchers, and students from the department, focused on the development of the extended stochastic scheduling model, the integration of surgeon-related constraints, and the adoption of the L-shaped solution approach. The feedback and questions received during the session provided new perspectives that will help strengthen the upcoming paper and my overall PhD work.

Overall, this research exchange was an exceptional experience that contributed significantly to the advancement of my doctoral research. Working under the guidance of Professor Iori and Dr. Caselli deepened my understanding of decomposition techniques and offered valuable insights into translating theoretical models into practical applications. The visit also fostered strong academic connections that I believe will lead to further collaborations in healthcare optimisation.

I am sincerely grateful to OPTIMA for supporting international collaboration. The exchange not only enhanced my technical and methodological skills but also expanded my academic network, reinforced my confidence as an independent researcher, and provided a unique opportunity to engage with world-leading experts in operations research. This experience has been instrumental in shaping my future research directions and preparing me for postdoctoral opportunities in optimisation and healthcare analytics.