## 5 Simulations
### Case Study Description  
**Hospital Description. ** The HCU is a public hospital located in Zaragoza, Spain providing health services to around 325,000 people, and it is a reference center of specialized attention of a population over 1 million inhabitants. The hospital has 800 beds and 15 ORs for major surgery, which is performed by eight different surgical departments. The case study considers the Orthopedic Surgical Department (OSD). The OSD is composed of five medical teams and has assigned 3 ORs (\(OR_{1}\), \(OR_{2}\) and \(OR_{3}\)) from 8:30 a.m. to 3:00 p.m. every day. Although there are other time blocks available for the department, the case study considers only these three ORs because the other ones have a variable time-table depending on the urgent surgeries. \(OR_{1}\) and \(OR_{2}\) are used to perform surgeries of elective patients, while OR3 is assigned to perform urgent surgeries. Table 5 shows an example of the weekly OR time-table of this OSD. According to Table 5, each medical team has two time blocks per week for performing surgeries on the elective patients. **Methodology of the case study. ** The main objective of the developed software tool is to improve the efficiency and quality of the surgical service. Thus, in the case study, the scheduling obtained manually is compared with the scheduling obtained by using CIPLAN. The methodology is as follows:  
1. Analysis of manual scheduling. Considering historical data of one medical team of the OSD, 36 consecutive OR time blocks of elective patients are analyzed. For each time block, the following information is obtained:  
* the type of surgeries performed,
* the starting and ending time of each surgery (real duration),
* the expected and real occupation rate,
* the confidence level of not exceeding the available time,
* the real ending time of each block. The effective time in a surgery block is the time of using the OR for surgeries; therefore, the occupation rate in a time block is computed as the effective time divided by the total time. 2. Create the waiting list. The manual scheduling and consequently the surgery types in the waiting list are known. However, the preference order of each surgery in the waiting list is unknown. In order to be able to obtain an ordered waiting list from which the scheduling using CIPLAN is performed, it is assumed that the position of the patients (surgeries) in the list corresponds to the order in which they were operated by using the manual scheduling. That is, the first patient in the waiting list is the first patient operated in the first time block. Thus, considering the surgeries performed in the 36 time blocks, an ordered waiting list containing 111 patients is created. 3. Scheduling using CIPLAN. The data necessary to perform the scheduling using CIPLAN are included in the tool and then the scheduling is performed:  
* All elective surgery types are added to CIPLAN including their average duration and standard deviation (computed considering historical data of the team during last two years). * A new medical team (team 1) is added to the tool. Moreover, a new doctor is added to the team. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **OR 1** & **OR 2** & **OR 3** \\ \hline
**Mon** & team 1 & team 2 & team 3 \\
**Tue** & team 4 & team 5 & team 1 \\
**Wed** & team 2 & team 3 & team 4 \\
**Thu** & team 5 & team 1 & team 2 \\
**Fri** & team 3 & team 4 & team 5 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: OR time-table in the Orthopedic Surgical Department of the HCU. All patients in the waiting list constructed using the 36 time blocks are assigned to the doctor. * For the next three months, two time blocks are booked weekly from 8:30 a.m. to 3:00 p.m., in total being 24 time blocks. * Using CIPLAN, the 24 time blocks previously booked are scheduled considering a minimum confidence level of not exceeding the total time equal to 69%. This value is fixed by doctors. 4. Analysis of the scheduling performed using CIPLAN.