# New Possibilities of Using DEMATEL and ERPN in the New PFMEA Hybrid Model
## 4 Conclusions  
The aim of the paper was to create a new hybrid model PFMEA-DEMATEL-ERPN for practical requirements. One of the requirements was how to overcome the limitations of conventional PFMEA for the effective design of measures. The second request contained a proposal on whether it is possible to incorporate the costs arising as an effect of the failure mode into the PFMEA. DEMATEL was used as a tool to estimate the functionality of the proposed models. This required high-quality experts in the field of process knowledge. When used as an estimation tool, it requires high-quality experts in the area of the process under study. The extended risk priority number ERPN ensured the inclusion of costs as consequences of failure in the model, and the inputs to the model were used during the construction of the economic model to evaluate the models from an economic point of view as well. In addition, the ERPN model also ensured that the limitations of the conventional PFMEA were overcome. Both models reduced the monitored criteria proposed by the aim of the paper. The conventional PFMEA reduced the monitored criteria the least; moreover, in practice, it brought a few critical situations when it was difficult to prioritize failure modes for the design of measures. Our research shows that for the 12 failure modes, we identified several failure modes with the same RPN and the same occurrence of O. We managed to solve this problem with both the DEMATEL model and the ERPN model. Our research paper deals with real problems in practice (operations, technology, and product) and guides on how to effectively use DEMATEL in managing these problems. In our paper, we have proved both the positives of the DEMATEL model in combination with PFMEA, which many other authors have completed as well [31; 32; 33; 34; 35; 36; 37; 38; 39; 45; 46], and the ability to specific situations where PFMEA is unusable, where it is necessary to use the DEMATEL model. We achieved the following benefits in our work:  
* Use of an innovative combination of models within the hybrid model;
* Defining border situations where conventional PFMEA is of limited applicability;
* Defining border situations when it is important to use the DEMATEL and ERPN model for PFMEA;Using the prediction of model functionality estimation based on the DEMATEL model and confirming its success (extended innovative use of the well-known DEMATEL model);
* Reduction in monitored criteria (occurrence of defective products, probability of occurrence of failure modes, and resulting risk number) for designed models;
* Designing and evaluating the economic benefits of the models (extended innovative use of ERPN);
* Proving the economic benefits of the models. The proposed models solved real problems in practice and provided instructions on how to effectively use them to solve problems in the production process. The proposed ERPN and DEMATEL models combined with conventional PFMEA have shown their validity in solving various requirements of manufacturers. It is important to emphasize that the results are applicable if we have identified failure modes with the same RPN in the PFMEA analysis. This means that the PFMEA has reached a limit regarding the prioritization of the proposed measures. Conceptualization, M.B. ; methodology, M.B., M.K. ([PERSON]) and C.K.L. ; validation, M.B., M.K. ([PERSON]) and C.K.L. ; formal analysis, M.B. and C.K.L. ; investigation, M.B. ; resources, M.B. ; data curation, M.B., J.B. and M.K. ([PERSON]); writing--original draft preparation, M.B. ; writing--review and editing, M.K. ([PERSON]) and M.B. ; visualization, M.B. ; supervision, M.B. ; funding acquisition, M.B. All authors have read and agreed to the published version of the manuscript. This research work has been supported by Ministry of Education, Science, Research and Sport of the Slovak Republic by the grant VEGA: 1/0236/21 and by Drive4 SIFood 313011V336, co-financed by the European Regional Development Fund. Not applicable.