# Automatic Failure Modes and Effects Analysis of an Electronic Fuel Injection Model
## 3 Automatic FMEA System  
### Automatic FMEA  
Automatic FMEA is a safety analysis tool that performs fault simulation in a Simulink environment to evaluate the failure effects of the design target system. Automatic FMEA restructures the Simulink model to perform fault simulation. The Simulink model consists of hierarchically connected functional blocks. In Simulink, one can express the algorithm using the block, which is an MDL file in the Simulink internal system. Automatic FMEA parses the Simulink MDL file to restructure into a suitable model for the fault injection process. In the restructured model, we insert a saboteur block between the original system blocks so that it can perform the fault injection simulation. We explain the internal process of the automatic FMEA shown in Figure 1. First, we use the safety requirements and design documents of the target system to identify the range of tolerance of the design parameters of the system [2; 4]. Using the results, we can identify the severity of the failure effects for the given failure modes, which is accomplished by injecting the corresponding faults into the target system. Second, we create a fault model corresponding to the failure modes using the design parameters of the target models, and perform fault simulation to evaluate the failure effects. In the model-based design process using Simulink, the target model has to be verified using the Simulink Design Verifier. After this process, the fault models are built using the selected HAZOP guidewords corresponding to the design parameters of the target model. During fault injection simulation, we inject these fault models representing a specific failure mode, and record the results of the fault simulation, which are used to identify the failure effects. Third, using the results of the fault simulation, we build the failure information that can be used for the FMEA report. Using the results of the fault simulation, it is possible to identify the local effect, the next effect, and the end effect of the given failure modes. Moreover, using the failure decision rules, we can identify the failure effects, which are the severity and occurrence rate of the failure modes. Using these as the information, we may build the preliminary FMEA report that can not only accelerate the FMEA process, but also be used to find the unidentified failure modes by the FMEA committee members, which may happen in the case of a new system's development. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Features** & **Automatic FMEA** & **HiP-HOPS** & **MADe** & **Relex** \\ \hline Environment & Simulink & Simulink & MADe FMEA & Spreadsheet SW \\ Failure Assessment & Automatic & Semi-automatic & Automatic & Manual \\ Failure Effects Analysis & Fault injection simulation & Manual simulation & Fault injection simulation & \\ Severity & & FTA & User manual & \\ Occurrence & Rule-based system & FTA & MADe-FTA & Manual \\ Detection & & N/A & N/A & \\ Fault Injection & Saboteur & N/A & Mutation & N/A \\ Mechanism & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison of various types of FMEA tools. In order to develop automated FMEA analysis tools in the Simulink environment, it is necessary to establish solutions to three development problems: The first is \"How to track the failure impact of FMEA's failure mode?\" One of the purposes of FMEA analysis is to track the potential impact of the system due to failure. In the traditional FMEA process, the knowledge and experience of the member of the FMEA committee are important for the identification of the failure. In model-based development, the model itself can be used as a tool to track the impact of failure. Automatic FMEA uses a Simulink model tree generation algorithm to trace the impact of failure in the model. This is described in detail in Section 3.2.1.