# Reliability and Risk Centered Maintenance: A Novel Method for Supporting Maintenance Management
## 4 Case Study
\begin{table}
\begin{tabular}{p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt}} \hline \hline
**Failure Mode ID** & **Failure Mode** & **FMRL** & **Failure Mode Management Policy** & **Maintenance Task** & **Task Frequency** \\ \hline FM.2.1A & Gate locked in a closed position & High & Scheduled restoration or replacement & Align the gate guides and free them from obstacles. & Follow the unit maintenance downtime plan \\ \hline FM.2.1B & Inoperative drive system & High & Scheduled restoration or replacement & Inspect the hydraulic system, retighen gaskets and connections, and replace components such as bearings and seals & Follow the unit maintenance downtime plan \\ \hline FM.2.1C & Gate locked in an intermediary position & Medium & Scheduled restoration or replacement & Align the gate guides and free them from obstacles. & Follow the unit maintenance downtime plan \\ \hline FM.2.1D & Low pressure in the hydraulic drive system & High & Scheduled restoration or replacement & Inspect the condition of the hydraulic system and correct leaks. Check the drive oil level and top up if necessary & Follow the inspection route plan \\ \hline FM.2.1E & Lack of watertightness in the water intake system when closed & Low & No scheduled task. Redesign may be desirable & - \\ \hline FM.2.1F & Auto-close command not executed & High & Scheduled restoration or replacement & Periodically replace the drive components of the automatic gate-closing system & Follow the unit maintenance downtime plan \\ \hline FM.2.1G & Gate locked in an open position & High & Scheduled restoration or replacement & Align the gate guides and free them from obstacles. & Follow the unit maintenance downtime plan \\ \hline FM.2.2A & Deformed or ruptured water intake grids & High & Scheduled restoration or replacement & Check the structural condition of the water intake grids from visual inspections. Carry out repairs when necessary & Follow the unit maintenance downtime plan \\ \hline FM.2.2B & Water intake grids are completely clogged & High & On-condition task & Continuously monitor the water pressure upstream and downstream of the grids and clean them with a different grade cleaner whenever the pressure difference is significant & Continuous \\ \hline FM.2.2C & Water intake grids are partially clogged & High & On-condition task & Continuously monitor the water pressure upstream and downstream of the grids and clean them with a hydraulic gate cleaner whenever the pressure difference is significant & Continuous \\ \hline FM.6.7A & Excessive clearance in the bearing housing & Medium & Scheduled restoration or replacement & Check the bearing housing fastening elements and retighen or replace them when necessary & Follow the unit maintenance downtime plan \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Failure mode management policies and maintenance tasks. \begin{table}
\begin{tabular}{l l l l l l} \hline \hline
**Failure** & **Failure Mode** & **FMRL** & **Failure Mode** & **Maintenance Task** & **Task Frequency** \\
**Mode ID** & **Failure Mode** & **Management Policy** & & & \\ \hline FM\&6.7\&B & Insufficient lubrication & High & On-condition task & Continuously monitoring oil flows and levels throughout the bearing lubrication system & Continuous \\ \hline FM\&6.7\&C & \multirow{2}{*}{Inadequate viscosity of oil} & \multirow{2}{*}{High} & \multirow{2}{*}{On-condition task} & Analyze the quality of the oil and replace it in case of contamination & Follow the oil analysis plan \\ \cline{4-4} \cline{6  
The same reasoning was developed for each failure mode under consideration. For each case, starting from the FMRL established for the specific failure mode, the corresponding decision diagram was navigated based on the responses provided to each question.