## 8 Conclusions  
In Spanish hospitals, doctors are responsible for scheduling of elective patients. Currently, this task is performed manually and has three main problems: (i) doctors need to spend their time in the administrative task (scheduling); (ii) usually under or overutilization of the ORs is obtained; and (iii) objectivity can be questioned due to fact that the scheduling is done by a human. This paper presents a _Decision Support System_ (DSS) that uses a _specific heuristic algorithm_ SHA, in order to help the hospital managers in the scheduling of the elective patients.  
Considering the duration of the surgeries and of the cleaning time as random variables with normal probability density function, the SHA with some statistics concepts can be used to schedule the elective patients from the waiting list to the next time blocks in such a way that: (i) the occupation rate of the time block is maximized; (ii) ensures a minimum confidence level of not exceeding the available time; and (iii) respect as much as possible the order of the patients in the waiting list. In addition, the DSS also includes features enabling the management of the medical teams and the OR time-table, updating the waiting list of patients, iterative planning, and automatic improvement of the input data.  
In collaboration with the Orthopedic Surgery Department of the _\"Lozano Blesa\"_ Hospital in Zaragoza, a software tool (CIPLAN) based on the proposed DSS has been developed. The preferences and concerns of doctors have been considered not only at the surgery scheduling level, but also at the user interface level. Thus, a friendly interface divided into six main panels is proposed in CIPLAN. It has been developed in Java language and uses a SQL database. Moreover, in order to provide a safe environment to work and better security of the medical data, different access levels are provided to every user.  
Finally, in order to check the impact of the software tool in the efficiency and the quality of the surgical service, a case study considering real data from the Orthopedic Department of the HCU has been discussed. The results show that, using CIPLAN, an improvement in the occupation rate of the ORs can be reached.  
However, it has been observed that there are significant differences in the surgery duration depending on the experience and on the surgery skill of the surgeon. Thus, if the SHA works with general average duration, over and under occupation rates are obtained more frequently than if it works with customized data. It would be convenient to customize the data of the surgical durations depending on each specific surgeon. In this way, the expected occupation rate and the expected ending time will be more similar to the real ones improving the quality of the service.  
As future work, a new panel in CIPLAN can be developed that, once a time block has been finished, allows doctors to compare in a visual way the expected scheduling and the real execution. On the other hand, a new feature in CIPLAN can be included that enables them to perform virtual scheduling in which all patients in the waiting list are scheduled. In this way, an approximated date could be given to patients from the moment when they are included in the system. Moreover, other extensions can be developed--among others, an app connected to CIPLAN allowing patients to know the approximated date of their surgeries.