## 4 Discussion  
The results show that the methods and tools of modular design are not currently aligned with those of prosumers (Figures 2 and 3). Their exit objectives differ in relevant aspects such as the beneficiary profile (industry vs. consumer) or the level of intervention (massive vs. particular). Figure 4 also shows only some common characteristics between both. Why are there not more points in common? Modular design could include more prosumer-related areas such as co-creation or DIY. However, its current development has not evolved in those directions, although it has the potential to do so due to the benefits it offers. Despite this, it is increasingly common to use modular design as a way to achieve the goals of the prosumer not only in customization, but also in the adaptation and evolution of their own products. It is detected that the boundary between adaptation and personalization is diffuse, since it is difficult to detect the changes that respond to a need (adaptation) from those that respond to a desire (personalization).  
Although they are scarce, the current common aspects between modular design and prosumer can form the basis for building a model. It is detected that some connections are influenced by the process or by the design group to which they are directed. While modular design is primarily aimed at professional designers and companies, both individually and collectively, prosumer tools are mostly aimed at individual users. This raises questions such as why there are not more relationships or why there is not a method for this yet. Nevertheless, there is the possibility that there will be more points in common using a new model that poses new relationships. There may still be relationships to be covered between modular design and prosumers due to the lack of connection points that are not currently covered, or others that have not been detected for lack of references.  
The design model must take into account the link between modular design and prosumers. It is observed that modular design already covers certain basic needs of the prosumer such as customization, adaptation, evolution or sustainability. However, it still does not allow co-creation by offering only a selection of modules. For this reason, the creative phases are currently not collective. In the case of industry, there may be co-creation by business decisions, although this is not the most common approach. On the contrary, in the case of prosumers, design decisions are mainly individual, and ideas are not shared with others with the same frequency as in the maker field. Could there be an intersection between both that leads to collaboration? Simplifying the design by employing several users or sharing modules could be two possible methods of collaboration. To achieve this, it would be necessary to remove the border between industry and prosumers through a global vision of co-creation.  
Considering the topics presented in this work, there are different future research directions that can be continued. The most obvious is the complete development of the proposed model following the guidelines set out. For this, it would also be necessary to define how to introduce it effectively to users by analyzing other similar models [53; 54]. On the other hand, the possible limitations of the model should also be analyzed, answering questions such as the proximity to the user/prosumer, applicability in multiple sectors of the industry or its operation with very complex elements, among others. In this regard, the feasibility of applying the method only to the prosumer or to the industry should also be analyzed.