## 5 Conclusions  
The papers describe a method and a tool proposition that enables the identification of welding design issues during the CAD development of a welded product/structure. This system allows the analysis of the rules propagation in the CAD design environment and the distribution of \"know-how\" to designers in the context of their specific design activity (explicit knowledge). This research encompasses several disciplines (e.g., welding knowledge classification, 3D model feature recognition, computational analysis) and proposes a framework to develop an engineering design tool extending the current average CAD capabilities. The adoption of the proposed approach highlights several findings. The first is related to the effort and time required to develop welding-compliant products and avoid welding operation issues in the construction yard. With this approach, design review loops may be reduced, thus improving the product time-to-market and the overall product quality. Another interesting outcome concerns the possibility to share manufacturing knowledge on welding technology across members of a design team and reuse it each time it is needed. With regards to this advantage, there is the possibility to use the proposed approach for teaching initiatives and to educate the young generation of designers with a learning-by-doing system. The case studies presented in this paper refer to two metal structures (a jack adapter of a heavy-duty prop and a lateral frame of a bracket structure) fabricated with arc welding processes. The increasing complexity highlighted for managing these products points researchers toward the adoption of algorithms and software tools for automating the methodology presented in this paper (e.g., software integrated with 3D CAD system). The approach presented in this paper is the backbone of a software tool for virtual assisting designers in evaluating possible design inconsistencies with manufacturing processes. Few limitations were observed with the development of the proposed methodology and framework. The first concerns the daily update of the DFW rules repository. This process requires the continuous analysis of new documents to retrieve additional tacit knowledge that can be translated into explicit knowledge by the use of the proposed knowledge-based system (rule insertion form). This drawback requires the involvement of a dedicated person who is in charge of new rules collection and database updates. The second one concerns the possibility to estimate the saving gained by the implementation of the proposed guidelines. Indeed, the estimation of economic key performance indicators (KPIs), such as the manufacturing cost starting from the analysis of 3D product features, will allow quantifying the differences between the original design and optimized design. Due to the limitations mentioned above, future studies will focus on two main topics, namely, (i) enlarge the DFW rules collection and (ii) assess KPIs based on design parameters (i.e., costs).  
Conceptualization, C.F. and F.C.; methodology, C.F.; software, F.C.; validation, R.G.; formal analysis, F.C.; investigation, C.F. and R.G.; resources, R.G.; data curation, R.G.; writing--original draft preparation, C.F.; writing--review and editing, F.C. and R.G.; supervision, C.F. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The authors declare no conflict of interest.