## 2 Materials and Methods
### Step 4: Scenario Modeling  
This section is dedicated to scenario modeling, which facilitates simulating different use case scenarios, and furthermore attaining an understanding of sensitive data and influencing factors identified through the model outputs. To do so, four different use case scenarios are modeled with the purpose of highlighting the associated sensitiveness connected to the model input data i.e., failure rates and MTTR values extracted from either (1) the case study, (2) the well-known OREDA database, [17] which is highly applied in the O&G industry, or (3) both. In final, the last use case scenario (use case scenario 5) that concerns the loading and deterioration process of the case study is modeled. Its purpose is  
\begin{table}
\begin{tabular}{c l c c c} \hline \hline
**Component** & **Failure Mode** & **Failure Mode Abbreviation** & **Case Study** & **OREDA Database** \\ \hline \multirow{4}{*}{Rotor} & Abnormal instrument reading & AIR & X & - \\  & Breakdown & BRD & X & - \\  & Low output & LOO & - & X \\ \hline \multirow{4}{*}{Bearing} & Abnormal instrument reading & AIR & X & X \\  & Breakdown & BRD & X & - \\  & Parameter deviation & PDE & - & X \\  & Vibration & VIB & - & X \\  & External leakage—Utility & ELU & X & - \\  & medium & & & \\ \hline \multirow{4}{*}{Motor} & Abnormal instrument reading & AIR & X & - \\  & Breakdown & BRD & X & - \\  & Parameter deviation & PDE & X & - \\  & External leakage—Utility & ELU & X & - \\  & Detulum & & & \\  & Spurious stop & UST & X & X \\  & Fail to start on demand & FTS & - & X \\  & Minor in-service problems & SER & X & X \\ \hline \multirow{4}{*}{Seal} & Abnormal instrument reading & AIR & X & X \\  & Breakdown & BRD & X & X \\  & Parameter deviation & PDE & X & X \\  & Vibration & VIB & - & X \\  & External leakage—Utility & ELU & X & X \\  & medium & & & \\  & Spurious stop & UST & - & X \\  & Fail to start on demand & FTS & - & X \\  & Minor in-service problems & SER & - & X \\  & External leakage—Process & ELP & - & X \\  & medium & & & \\  & Low output & LOO & - & X \\  & Internal leakage & INL & X & X \\  & Unknown & UNK & - & X \\  & Other & OTH & - & X \\ \hline \hline \end{tabular}
\end{table}
Table 4: Differences in failure modes of centrifugal gas compressor presented by the empiric case study data and the offshore and onshore reliability data handbook (OREDA) database.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**From State** & **To State** & **Trigger** & **Logic** & **Data Source** \\ \hline Working & Failure & Rates & Parameter & Case study/OREDA \\ \hline Working 1 & Failure 1 & Condition 1 & Fault \textgreater{} 0 1 & Calixto 1 \\ \hline Failure & Corrective Maintenance & Timeout & Parameter & Fixed \\ \hline Corrective Maintenance & Normal Working & Timeout & Triangular distr. & Case study/OREDA \\ \hline \hline \end{tabular}  
* Only valid for the condition monitoring systems with detection and prediction capabilities. In this paper, this refers to intelligent maintenance.  
\end{table}
Table 5: The connection between states, triggers, logics, and data sources in Figure 4.  
to highlight the connection between component deterioration, detection, diagnosis, and prognosis purposes in the context of implementing an intelligent maintenance management system into the case study. Therefore, this paper models in total five use case scenarios. The connection between the input data and use case scenarios is summarized in Table 6 and described in more detail in the following subsections.