# A New Hybrid Dynamic FMECA with Decision-Making Methodology: A Case Study in an Agri-Food Company
## 3 Case Study
### Definition and Impact Assessment of Corrective Actions  
As seen, our machine's critical events concern the tunnel chain, the transfer chain, and the release guide. Through simulation, it was identified that the component that has the greatest impact on the trend of the machine failure rate is the chicken release guide. This component performs a fundamental task and must always be aligned in the right position. Unlike the chicken hooking guide which plays a similar role, its task is made more complicated by the fact that the chickens arrive from the cooling tunnel where they have stayed for at least 3 h. This period causes the chicken to fasten to the hook of the tunnel chain, arriving at the chicken release area, and the guide must undergo strong stress to be able to detach the chicken from the hook and must always be aligned correctly; otherwise, it runs the risk of spoiling or dropping the chicken (Figure 12). To avoid fewer failures and lower the chicken guide failure rate (Table 3), one might consider increasing the guide adjustment frequency. This first action allows us to lower the probability of the failure occurring drastically. Therefore, an 87.5% improvement in the guide failure rate is obtained with this first corrective action. Figure 11: AS-IS failure rate diagram. Therefore, to see how the situation changes in the case of the failure rate of the entire system, a significant improvement is also noted here, as can be seen in Table 4 and Figure 13 from a maximum of 8.23 to a maximum of 2.65, with an improvement of 67.8%  
Other actions that can be implemented to lower the entire system's failure rate are to try to increase the detectability of some failure modes before they occur. In particular, two scenarios can be evaluated to reduce the failure rate of the chains:  
The first scenario concerns the breakage of the electrical parts due to the blackout. Obviously, nothing can be done about it because it depends on external causes. The only actions that could be implemented to eliminate those failure modes are to install some emergency generators. However, this is a very expensive action that is not worth the risk due to the very low frequency of blackouts. The second scenario analyses the failure rate of the chains due to their wear. It could be established either by a greater number of checks by the maintenance technicians to  
Figure 12: The FM9 failure rate with maintenance every four months. AS-IS state: guide adjustment rate every two quarters. TO-BE state: guide adjustment rate every four months. Figure 13: AS-IS/TO-BE machine failure comparison. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Time (Quarter)** & **0** & **0.5** & **1** & **1.5** & **2** & **2.5** & **3** & **3.5** & **4** \\ \hline Failure rate FM9: STATUS & 0 & 0.1 & 0.8 & 0.1 & 0.8 & 0.1 & 0.8 & 0.1 & 0.8 \\ TO-BE every four months & 0 & 0.1 & 0.8 & 2.7 & 6.4 & 0.1 & 0.8 & 2.7 & 6.4 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: FM9 Failure rate. identify signs of wear of the chains or establish automatic checks with sensors capable of identifying chain length variations. The hypothesis is that it is possible to detect the fault of 90% of failures, thanks to one of these two choices. Figure 14 and Table 4 show how the situation changes can be seen. There is a minimum improvement of about 5% from the frequency of the chains' breakings which is already minimal. Indeed, it is advisable to increase the inspections by the maintenance technicians to intervene promptly at every slightest deviation of the chain from the initial conditions to avoid accelerated wear. However, installing automatic detection systems such as sensors is not advisable because they are still expensive systems. The first safe step on which to intervene is the chicken release guide. A few corrective actions achieve great results in machine operation, thus limiting production stops to a minimum.