Part 1: The TRL Scale: The Ladder to Climb
By Sebastian Engell and Svetlana Klessova
The goal of R&D projects is to bring technologies to new products or to repeated long-term use in an operational environment, starting from first investigations of the technical feasibility. This process is characterized by attrition – many projects are given up at a certain stage because of technical problems, lack of sufficient predicted return of investment, or lack of user acceptance. The development process is usually structured according to the so-called Technology Readiness Levels (TRL), which go back to NASA [1] and exist in different flavors (for an example, see Table 1).
Table 1: TRL scale used in European Commission (EC)-funded projects [2].
A TRL scale provides a basis for the discussion between developers, R&D managers, and funding institutions about what the goals of a specific phase of a specific development process are or which advancements are expected during the duration of a project. In the planning of R&D projects, assumptions have to be made about the expected efforts in terms of time, money and other resources when going up the TRL ladder, and it is important to anticipate the increase of the efforts with increasing maturity. The TRLs measure only the technical maturity, not commercial potential or return on investment. Therefore part 1 of our Leadership BRIEF explores the concept of the Technology Readiness Levels and introduces a refined definition of the TRL scale.
We performed an in-depth study [3] 38 development processes in which novel technical solutions (new devices, methods, tools, algorithms etc.) were developed starting from different initial levels to different final levels of maturity. The study aims to determine (1) how anticipate the increase of efforts for the development of technologies from an initial to a final state (e.g. from a first demonstration in the lab to a pilot implementation) and (2) how to assess and compare the advancements of different technologies in an R&D portfolio during a certain period (e.g. 1 year).
The study [3] focused on R&D projects at the interface of IT technologies and industrial systems. The new technologies were incremental rather than disruptive, which is characteristic for a large number of industrial R&D projects. The analysis was based on interviews with project participants and on the assessment and comparison of the time and effort needed to progress from one level to the next. It included 38 new technical solutions that were brought from TRL 3 or 4 to a maximum TRL of 8.
As there was clear feedback from the developers whom we interviewed that the meaning of the definitions of the TRL scale was not clear enough and that it would be better to define the progress of the maturity in smaller steps, we refined the TRL scale to provide a basis for an accurate analysis of the progression of the maturity of the technologies. We present this refined TRL scale below for the specific type of technologies that were studied in [3], but we believe that this provides a blueprint that can be easily adapted to other contexts. This refined definition of TRL is the basis for a scheme to anticipate the (relative) efforts that are needed to progress along the TRL ladder which we present in part 2 of this contribution.
In our refined definitions, we distinguish between a product which can be sold to and used by any customer, and roll-out which means the deployment of an innovative technology for permanent use within a known a company or institution. A product can be a physical component, a system, a new service, or a solution. We define a pilot as an implementation of the solution for the validation of its benefits for a significant period of time by the end users. In contrast, a prototype implementation means testing the main features of an innovative technology in the operational or in a synthetic environment by a provisional installation. A pilot must be significantly more stable and user friendly than a prototype.
In contrast to the TRL scale shown above in Table 1, the original TRL scale [1] distinguishes between components and systems and reflects the efforts that are needed for the integration of new components into larger (usually existing) systems. We follow this idea by defining maturity levels both for components and for systems.
Our refined TRL scale is presented in Table 2 below.
Table 2: Refined TRL scale defining the “ladder” for the assessment of the advancement of technologies, adapted from [3]
Besides being less ambiguous than the usual definitions, the above refinement reflects that the development process can progress along different paths: For example, a component can be developed up to TRL 6.1 and then be integrated into a system prototype (TRL 6.2) or the integration can be performed earlier, leading to a system prototype at TRL 5.2 which is then matured via TRL 6.2 to TRL 7. Similarly, one can progress from a successful pilot (TRL 7.1) to roll-out or development of a product, or alternatively do several pilot installations first. The definition of TRL 8 considers levels 8.2, 8.3 and 8.4 as the targets and 8.1 as an intermediate step.
With such a refined TRL scale, it is easier for project managers to define which maturity levels the projects should reach at which point in time, to anticipate the required efforts, and to monitor the progress and to take corrective actions if the progress is not as expected.
In part 2 of our Leadership BRIEF, we provide a scoring system by which the relative average efforts to mature a technology from an initial to a final TRL can be computed for the estimation of the required resources and for the comparison of the performance of similar projects.
Digging Deeper:
[1] Mankins, J. (2009). Technology readiness assessments: A retrospective. Acta Astronautica 65, 9–10, 1216-1223. https://www.sciencedirect.com/science/article/abs/pii/S0094576509002008?via%3Dihub (Accessed April 2, 2023)
[2] European Commission (2014). Horizon 2020 – Work programme 2014-2015. General Annexes. Annex G. Technology Readiness Levels (TRL). https://ec.europa.eu/research/participants/data/ref/h2020/wp/2014_2015/annexes/h2020-wp1415-annex-g-trl_en.pdf (Accessed April 2, 2023).
[3] Klessova, S., Engell, S., Thomas, C. (2022). Assessment of the advancement of market-upstream innovations and of the performance of research and innovation projects. Technovation, 116, 102495. https://doi.org/10.1016/j.technovation.2022.102495
About the authors
Sebastian Engell is Professor of Process Dynamics and Operations at TU Dortmund, Germany and IFAC Fellow. He received an ERC Advanced Investigator grant and has been involved in leading roles in numerous academia-industry R&D projects. You can contact him via his email sebastian.engell@tu-dortmund.de or LinkedIn Sebastian Engell.
Svetlana Klessova is Director, Research and Innovation Partnerships at G.A.C. Group, France, an international consulting firm in innovation and performance. Dr. Klessova has implemented 60+ projects around the world. Her PhD thesis and publications won several awards. You can contact her via email sklessova@group-gac.com or LinkedIn Svetlana Klessova.
