# Technology Readiness Levels (TRLs) in the Era of Co-Creation
## 2 Related Work
As co-creation produces something that did not exist before [21], this implies that the result of a co-creation process is to have created something or to have brought something into existence [22]. An interesting background to this treatise is the classification work on modern innovation presented in the literature by [PERSON] et al. [23]. These researchers start with a description of the three key types of innovation: single user innovation, where an individual or a firm contemplates investment in an innovative design; producer innovation, where producers undertake larger designs aiming at many end users; and open collaborative innovation, involving users and various third parties that collectively generate and share a design. The authors rigorously investigate the particular conditions affecting the costs incurred and the value generated to conclude on what effectively makes a particular setup helpful and competitive. They also discuss hybrid types of innovation, where more than one of the above three fundamental types coexist. We will argue below that co-creation is often a setup that cannot be well described by the current TRL scheme. According to the classification presented in this work, co-creation, in fact, is a hybrid innovation model, including aspects of the open collaborative innovation model and the producer innovation model. Apparently, the current TRL approach mostly reflects the producer innovation model that has been the dominant approach in the 20 th century. Indeed, [PERSON] [24] positions producers at the center of the innovation stage, stating that 'it is the producer who initiates economic change'. [PERSON] [25; 26] and [PERSON] [27] echoed [PERSON]'s views by suggesting that the vast majority of innovative design results in private profit-maximizing firms. The dramatic reduction of communication costs in recent times essentially enabled the open-source innovation model to emerge and occupy a measurable and increasingly important role in the innovation arena. To this extent, perhaps the current TRL model, by being based on the key hypotheses and practices of the 20 th century, may fail to fully and adequately model the maturity evolution of new-era innovations that are of the open-source model or are hybrids, sharing an important part thereof. The details of open collaborative innovation have also received increasing attention in the literature. [PERSON] [28], [PERSON] [29], and [PERSON] [30; 31] showed that the key condition for collaborative innovation to be a rational and potentially preferable option when compared to the produced innovation paradigm is that the communication costs incurred by each participant joining the collaboration are well offset by the value of the design contributed by the other parties. This condition essentially allows design modularity and propels open collaboration; it is a condition that is met more and more in current times, when the cost of communication is rapidly reducing. This comes in stark contrast to the centralized innovation model of the 20 th century, where the firm itself was by far the most suitable entity to innovate in mass-produced products and processes, something that is also well established in the literature [32; 33]. The high cost of communication in those days did not allow for the potential of open collaboration to be unleashed. Currently, the facility to locate and use several communication channels allows even the public sector to approach co-creation. Co-creation has also captured the attention of the public sector, as the new public management theory relies on the concept of collaborative interaction, networks, and partnerships with the private sector and industry. In the literature review, [PERSON] et al. [34] classified co-creation benefits in the public sector as innovation-related and improving decision making. According to the authors, the present context of austerity and reduced public resources has led policymakers and politicians to consider the benefits of co-creation, co-production, and innovation.