03:30 PM - 04:00 PM
Tactical and operational optimization of Operating Theaters: a multi-level decision support system
The high costs of health care push national and regional health services as well as local authorities to constantly improve management performances in order to obtain more efficient organization of hospitals activities and provide patients with the best possible care.
Tactical and operational planning decisions in Italy are classified as separate problems both in terms of time frame and in terms of decision makers. The tactical planning process is performed, on a monthly or quarterly basis, by the hospital management board and defines the assignment of operating room time slots to medical specialties. The operational planning process is performed, on a weekly basis, by the specialty head physician and defines the scheduling of patients in the assigned operating room time slots.
We present a multi-level decision support approach focused on a multispecialty Operating Theater for Emilia-Romagna region.
First, we present a tactical optimization model that calculates, on a monthly or quarterly basis, the assignment of operating room time slots to medical specialties in order to minimize: (i) the length of specialties waiting lists weighted by their relative importance for patients safety, (ii) the cost overrun, and (iii) the gap between the negotiated case mix and the final one. The final objective is a tradeoff between (i) and (ii), (iii).
Second, we present an operational optimization model that calculates, on a weekly basis, the subset of patients in the waiting list that will be scheduled for surgery treatment in order to: (a) comply with the regional guidelines related to maximum waiting time per pathology, and (b) significantly reduce the violation of time slots (overtime) and the misuse of surgical time (under-utilization).
Finally, we present a simulation model that integrates the tactical and the operational optimization models evaluating their effectiveness on a monthly or quarterly planning horizon.
04:00 PM - 04:30 PM
Logic-based Benders' Decomposition Approaches with Application to Operating Room Scheduling
We develop three novel logic-based Benders' decomposition (LBBD) cut generation approaches and a cut propagation technique to solve large-scale location-allocation integer programs (IPs). We show that each LBBD can be implemented in four different possible ways, giving rise to 24 distinct LBBD variants with completely different computational performances. LBBDs decompose the IP model into a location- and knapsack-based allocation master problem and multiple packing sub-problems. We illustrate the performance of our LBBDs on the distributed operating room scheduling problem, where patients and operating rooms are collaboratively scheduled across a group of hospitals, and the goal is to select patients with the highest priority scores and schedule them in the current planning horizon, while determining the number of surgical suites and operating rooms required to accommodate the schedule at minimum cost. We quantitatively demonstrate that the new Benders' cuts, cut propagation, and implementation can individually or collectively yield a computational time impact of at least one order of magnitude. We also demonstrate that our LBBDs are faster than IP+Gurobi and can find optimal solutions when IP+Gurobi cannot.
04:30 PM - 05:00 PM
A surgical case assignment problem in a block scheduling strategy
An adequate access to healthcare is one of the strategic axes considered in the Portuguese National Health Plan (PNHP). The strategic integration of the PNHP seeks to ensure the best performance and adequacy of care which maximize the use of resources, quality, equity and access. The demand for surgical care in Portugal tends to grow continuously ever since a systematic measurement was introduced. Hospitals are forced to make the most appropriate use of available resources in order to provide timely care to surgical requests. This work emerges from a close collaboration with the Administration of a publicly funded Portuguese hospital. This hospital has a central operating theatre with a large number of operating rooms shared by several specialties. The operating room time is pre-allocated to specialties (master surgery schedule) and each specialty schedules surgeries to its allocated time block and day (block scheduling strategy). In advance scheduling, also referred to as surgical case assignment problem (SCAP), patients waiting for surgery (elective patients) are assigned to an operating room and a day in a weekly planning horizon. Several versions for this particular SCAP are formulated in (mixed) integer programming: from the Administration’s intention up to the surgeon’s current practice. In preliminary results using hospital data, Cplex provided a feasible solution with a gap smaller than 1% in negligible time.