# The Impact of Additive Manufacturing on the Flexibility of a Manufacturing Supply Chain
## 5 Conclusions  
In the supply chain management literature, it has been emphasised that managing manufacturing systems should incorporate flexibility as a core objective along with cost, quality and dependability. There were no studies, however, that examined how adopting AM affects these flexibility aspects in response to certain market disruptions. This paper addressed this gap by developing a conceptual model that maps AM characteristics relevant to flexibility against key market disruption scenarios. This work offers novel insights into the relationship between AM and supply chain responsiveness that will inform future research and practitioners.  
To gain further insight into the developed conceptual model, a case study was undertaken that examined the effect of AM adoption on supply chain flexibility in comparison with other conventional manufacturing technologies. By conducting an inter-process comparison between AM and IM using data collected from a manufacturing company, the study provided some tentative quantification of these aspects. The AM supply chain without inventory in this case study was relatively ineffective in responding rapidly to different demand volumes (i.e., 58.70% for AM compared to 65.68% for IM) and delivery times (75.35% for AM compared to 92.8% for IM). Also, the supply chain that utilised IM would be more attractive when aiming at increasing volume flexibility due to the inverse proportion between the unit cost of its products and its volume flexibility. However, due to the lack of tooling, the AM route provided more flexibility in producing a wide range of products with less time (i.e., 0.33 h for AM compared to 4.91 h for IM) and at a lower cost when introducing new products to the system (@0 for AM compared to 630,000 for IM).  
AM might seem an attractive option when aiming at improving flexibility. However, it can also be less attractive relative to other manufacturing technologies and for certain supply chain flexibility aspects. These results particularly demonstrate the feasibility of adopting AM in production environments with demand volatility. When considering AM as a choice to increase supply chain flexibility in volatile environments that entails potentially high production volumes, AM might be ineffective compared to other dedicated manufacturing technologies. Furthermore, this study suggests that lead-time compression enabled by the on-demand production of AM technology will not be sufficient to outweigh the lead-time compression attained by a supply chain employing a buffer stock strategy produced by IM. On the other side, AM can significantly increase supply chain flexibility in production settings where customised products or low production volumes are demanded, attributed mainly to the lack of tooling in AM. The new product flexibility offered by AM can also play a key role in facilitating the application of agile product development that requires constant production of MVPs, a challenge that hinders the successful implementation of the smart factory. These results will inform both practitioners and scholars to predict the effects of AM adoption on distinct supply chain flexibility aspects.  
Conceptualization, A.A.A., M.B. and C.T.; methodology, A.A.A. and M.B; formal analysis, A.A.A.; investigation, A.A.A.; resources, A.A.A. and M.B.; data curation, A.A.A.; writing--original draft preparation, A.A.A.; writing--review and editing, M.B., C.T. and W.E.; supervision, A.A.A. and M.B.; project administration, A.A.A. and M.B. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Data Availability Statement: Not applicable.