# Reliability and Risk Centered Maintenance: A Novel Method for Supporting Maintenance Management
## 2 RCM and RBM Methods as Support for Maintenance
Therefore, it aims to reduce the overall risk in the operating facility by using the risk level as a criterion to plan maintenance tasks [PERSON] and [PERSON] (2003). While the two strategies have supported maintenance management over the last years, they are often approached separately. To the best of the authors' knowledge, no method has been proposed to integrate RCM with RBM to consider reliability and risk in a novel single methodology for decision-making on cost-effective maintenance plans. For instance, RCM was extended to consider a broader risk perspective with the use of an uncertainty analysis incorporated into the traditional RCM method [PERSON] _et al._ (2016). Moreover, RCM, Risk-Based Inspection (RBI), and Safety Instrumented Function Process (SIFpro) were merged into a new methodology that still treats RCM and RBI individually, sharing a common step of preparation [PERSON] _et al._ (2016). Nonetheless, these two works offer more of an expansion upon RCM by incorporating elements related to risk analysis, rather than outright merging RCM and RBM into a single method. For better comprehension, the main features of the RCM and RBM methods [PERSON] and [PERSON] (2003, 2003) as well as those considered for the proposed Reliability and Risk Centered Maintenance (RRCM) were analyzed and summarized in Table 1. \begin{table}
\begin{tabular}{l c c c} \hline \hline  & **RCM** & **RBM** & **RRCM** \\ \hline \multirow{4}{*}{Item study} & Select the item & X & X \\ \cline{2-4}  & Determine the functions and performance & \multirow{2}{*}{X} & \multirow{2}{*}{X} \\  & standards & & X \\ \cline{2-4}  & Determine functional failures/failure & & \\ \cline{2-4}  & scenarios & & X \\ \cline{2-4}  & Determine the associated failure modes & & & X \\ \cline{2-4}  & Determine the failure effects for each failure & & & X \\ \cline{2-4}  & Determine the failure consequence category & \multirow{2}{*}{X} & \multirow{2}{*}{X} \\  & (FCC) for the functional failures & & \\ \hline \multirow{4}{*}{Risk estimation and evaluation} & Perform hazard quantification/impact & \multirow{2}{*}{X} & \multirow{2}{*}{X} \\  & assessment & & \\ \cline{2-4}  & Perform a probabilistic assessment & & X \\ \cline{2-4}  & Estimate/classify the risk & & X \\ \cline{2-4}  & Set up acceptance risk criteria & & \\ \cline{2-4}  & Compare the assessed risk with acceptance & \multirow{2}{*}{X} & \multirow{2}{*}{X} \\  & criteria & & \\ \hline \multirow{4}{*}{Maintenance planning} & Select the failure management policy based & \multirow{2}{*}{X} & \multirow{2}{*}{X} \\  & on FCC & & \\ \cline{2-4}  & Select the failure management policy based & \multirow{2}{*}{X} & \multirow{2}{*}{X} \\  & on the failure mode risk classification & & \\ \cline{2-4}  & Apply a decision tree diagram as support for & & \\ \cline{2-4}  & cost-effective decisions & \multirow{2}{*}{X} & \multirow{2}{*}{X} \\  & Determine maintenance tasks and interval & & \\ \cline{2-4}  & Determine maintenance plans to reduce risk & \multirow{2}{*}{X} & \multirow{2}{*}{X} \\  & to items that exceed the acceptance criteria & & \\ \hline \multirow{4}{*}{Periodic review} & Re-estimate/reclassify the risk & \multirow{2}{*}{X} & \multirow{2}{*}{X} \\  & Review the input information and decisions & & \\ \cline{1-1} \cline{3-4}  & made & & \\ \cline{1-1} \cline{3-4}  & & & \\ \cline{1-1} \cline{3-4}  & & & \\ \cline{1-1} \cline{3-4}  & & & \\ \cline{1-1} \cline{3-4}  & & & \\ \cline{1-1} \cline{3-4}  & & & \\ \hline \end{tabular}
\end{table} 
Table 1: Comparison of main features of RCM, RBM, and RRCM methods. As can be seen in Table 1, the RCM establishes a more detailed study of the item under analysis when compared to the RBM. As it is oriented to reliability, it needs a deep understanding of the item's functions and functional failures, to later determine what shall be carried out to ensure that the item continues to do what its users want it to do in its operational context.