# Risk Assessment in the Design of Railroad Control Command and Signaling Devices Using Fuzzy Sets
## 2 Input Data
### Analysis of Risks Occurring in Railway Investment Processes  
In investment processes, risk analysis is an important element of the design, production, and operation of systems and subsystems. Provisions appearing in some standards for rail traffic control devices and systems, especially those related to safety, even impose on design teams and device manufacturers the obligation to carry out a risk analysis. Data on the most common risks in investment processes involving the modernization of the rail traffic control subsystem were presented and analyzed in the dissertation in Ref. [1]. The risks presented in Ref. [1] were determined on the basis of surveys and workshop meetings, and then they were analyzed and grouped depending on the area they concerned. Eight risk groups were identified in the following areas:* Signal box;
* Cable infrastructure;
* External devices;
* Interfaces;
* Cross-industry coordination;
* Administrative and legal requirements;
* Cooperation with the infrastructure manager;
* Other. Based on the data collected in Ref. [1], an original method of risk analysis was presented, which was mainly based on calculating the risk level for each risk factor. For this purpose, for each risk factor present in a given investment process, the following should be specified:  
* Urgency (PCR)--how quickly preventive actions should be implemented to mitigate the risk. There are four levels of urgency: urgent, imperative, mandatory, and recommended. * Greatness (WCR)--the degree of damage, i.e., how serious the consequences of a given threat can be. Four levels were defined: critical, high, medium, and low. * Difficulty (TCR)--the degree of difficulty of introducing measures to eliminate a given threat. Four levels of difficulty were defined: impossible, difficult, medium, and easy. \[cr_{EI}=\langle P_{CR},W_{CR},T_{CR}\rangle \tag{1}\]  
where  
\(cr_{EI}\)--risk factor for a given stage of the investment and the stakeholder;  
\(P_{CR}\)--urgency, \(P_{CR}=\{p_{i},\dots\}\), \(i=1,\dots 4\);  
\(W_{CR}\)--greatness, \(W_{CR}=\{w_{i};\dots\}\), \(i=1,\dots 4\);  
\(T_{CR}\)--difficulty, \(T_{CR}=\{t_{i};\dots\}\), \(i=1,\dots 4\);  
\(E\)--stage of investment implementation, \(E=\{e_{i};\dots\}\), \(i=1,\dots 4\);  
\(I\)--stakeholders, \(I=\{i_{i};\dots\}\), \(i=1,\dots 4\). For each risk factor, the risk (\(R_{CR}\)) can be calculated by multiplying the urgency (\(P_{CR}\)), the weighting of the magnitude of the risk's impact (\(W_{CR}\)), and the difficulty (\(T_{CR}\)):  
\[R_{CR}=P_{CR}\times W_{CR}\times T_{CR} \tag{2}\]  
Urgency \(P_{CR}\) can take the following values:  
\[P_{CR}=\left\{\begin{array}{l}4\;\textit{when\;\;\;\;\;\;\;\;\;\;\;\;\;\; \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\; \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\; \;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\The greatness \(W_{CR}\) can take the following values:  
\[W_{CR}=\left\{ \begin{array}{l}4\;\textit{when critical}\\ 3\;\textit{when high}\\ 2\;\textit{when medium}\\ 1\;\textit{when low}\end{array} \right. \tag{5}\]  
The greatness \(W_{CR}\) categories are set out in Table 3, with the given numerical values and a description of each category. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Vrigency Assessment (\(P_{CR}\))** & **Category Name** & **Description** \\ \hline
4 & Urgent & Requires immediate action \\
3 & Imperative & Requires preventive action in the short \\
2 & Mandatory & Requires preventive actions that can be \\  & & postponed and periodic monitoring \\  & & The introduction of actions is \\
1 & Recommended & recommended, but not mandatory and \\  & & not time-bound. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Evaluation of the urgency category (\(P_{CR}\)).