# Automatic Failure Modes and Effects Analysis of an Electronic Fuel Injection Model
## 3 Automatic FMEA System
### The Function of Automatic FMEA
#### 3.2.2 Saboteur-Based Fault Simulation Model Creation  
Automatic FMEA builds a simulation model for the fault injection campaign to analyze the failure effects for given failure modes by applying the saboteur module to the Simulink MDL file. In the saboteur technique, we may append a saboteur block between the design blocks so that it can insert faults into the design model. The saboteur block converts the value of a variable into a faulty value according to a fault model specified by the fault injection campaign. The saboteur technique has the advantage of being able to create a failure test model in a simple manner. However, the process of adding saboteur blocks may alter the original functionality of the design model. In order to maintain the consistency between the original model and the fault simulation model, we perform a verification simulation using Simulink Design Verifier and the benchmark experiments, which compares the results of the simulation with and without the saboteur block in the design model. The saboteur block of automatic FMEA injects a fault model from the set of faults listed from the fault injection campaign. The fault model illustrates the failure modes using (1) a fault model, (2) a fault occurrence time, and (3) a fault duration time. The fault model is constructed by applying a HAZOP guideword to each and every variable available in the Simulink design model. In automatic FMEA, we multiply the value of the design parameter of the Simulink model by the proportional coefficient using the failure keyword as shown in Table 2. For example, suppose the parameter \"A\" replies with the \"less than requested\"  
Figure 3: Building the failure propagation list using the inter-block and the intra-block link information of the Simulink model tree extracted from the Simulink design model. failure keyword. Then, it builds the three-fault model using 90%, 80%, and 70% of the value of the parameter \"A\" after the consultation with the domain experts. In this way, various types of failure effects may be investigated in a quantitative manner using the derived fault models, so that the automatic FMEA may contribute to discovery of the unseen failure mode by the members of the FMEA committee. Automatic FMEA integrates the saboteur blocks with the blocks in the simulation models to facilitate the simulated fault injection campaign. Let us assume that a block in Simulink is connected with a port key and a line key, where the port key is an input or output identifier of a block, and the line key is a link of two blocks. Automatic FMEA searches for the port key and line key of the block corresponding to the fault injection location to add the saboteur block and modify its value. The original design model and the model prepared for the fault injection experiments are compared in Figure 4. The required number of the fault simulation design model is created, and the injection process proceeds automatically so that we may accumulate a large amount of the failure mode-failure effects relationship information for the Simulink design model. In the figure, a saboteur block is added between each block to implant a defect. Automatic FMEA performs the Simulink fault injection simulation of the preparation, execution, and the collection of the simulation log for the fault models described in the fault injection campaign. Figure 4: Standard Simulink model (**up**) and Simulink model with the saboteur fault injection block (**down**). Automatic FMEA controls the saboteur block added to the Simulink model to perform a failure simulation, as shown in Figure 5. In a normal case, the output from the front logic block is transferred to the back-end logic block via the correct data (CD) block. In the case of the fault injection simulation, one of the outputs of the failure data (FD) block is transferred to the back-end logic block according to the fault injection scenario. The automatic FMEA controls the saboteur block using the MATLAB command script [43].