## 4 Discussion  
The best maintenance strategy was determined for each of the healthcare centers analyzed based on the results of the study. This maintenance strategy should prevent the selected system from reaching a state higher than the tolerable state (5). This is of utmost importance in healthcare buildings, the facilities of which are vital for patients [36]. In many cases, making decisions in the health sector is very difficult due to its complexity and its influence on the life quality of people [37]. The authors found that the combination of two maintenance policies ensures that the system is always appropriate, and that, therefore, the joint implementation of the two policies is much better than separate implementation. For this reason, it would be convenient to conduct a study every 6 months of  
Figure 5: Bar graph of maintenance periodicity.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{2}{c}{**2 nd Option**} & \multicolumn{4}{c}{**4 th Option**} \\ \hline
**Healthcare** & **Incidents** & **Periodicity** & **Healthcare** & **Incidents** & **Periodicity** \\
**Centers** & **Incidents** & **(Weeks)** & **Centers** & **Incidents** & **(Weeks)** \\ \hline
3 & 42 & 1 & 1 & 21 & 3 \\ \hline
4 & 19 & 3 & 2 & 32 & 2 \\ \hline
6 & 27 & 2 & 5 & 23 & 3 \\ \hline
8 & 20 & 3 & 7 & 38 & 2 \\ \hline
9 & 30 & 2 & 10 & 33 & 2 \\ \hline
11 & 15 & 3 & 15 & 32 & 2 \\ \hline
12 & 14 & 3 & 16 & 31 & 2 \\ \hline
13 & 41 & 1 & 18 & 36 & 2 \\ \hline
14 & 17 & 3 & 19 & 21 & 3 \\ \hline
17 & 41 & 1 & 24 & 34 & 2 \\ \hline
20 & 18 & 3 & 25 & 26 & 3 \\ \hline
21 & 12 & 3 & & & \\ \hline
22 & 44 & 1 & & & \\ \hline
23 & 42 & 1 & & & \\ \hline \hline \end{tabular}
\end{table}
Table 5: Classification of healthcare centers.  
the average incidents found in each of the 25 healthcare centers to readjust the maintenance policy and adjust the periodicity [38].  
The Markov chains have proven to be useful to determine the best maintenance strategy for healthcare buildings. With this probabilistic tool, the most appropriate maintenance policy can be determined, which prevents healthcare centers from exceeding a certain degree of degradation, thus guaranteeing the functioning of the system and the safety of the patients [39]. It also allows for planned and implemented maintenance strategies to save time and costs [40], which is one of the main objectives of hospital engineering [41].  
This method was also found to allow for maintenance planning with more appropriate periods, which translates into savings in respect of travel costs and time spent on maintenance tasks. This optimizes the use of these resources and their possible use in other aspects. Also, the maintenance technician emits less CO\({}_{2}\) during his or her travels. The use of Markov chains for preventive maintenance planning is, therefore, part of a strategy based on circular economy [42], meeting savings and emission reduction targets. The outcome of this research is useful for planning the maintenance of healthcare centers, guaranteeing an appropriate level of maintenance according to the failures, and can be extrapolated to other buildings in the tertiary sector with similar complexity [43].