Abstract
At present, the TRL scale is used as an instrument in decision making regarding investments in research and development also at EU level. This requires different methods to make this instrument operational by adjusting (or understanding) TRL definitions. The scale must be adapted to the specific purpose of the funding by the EU of CDI programmes, because it does not approach the feedback mechanisms that are part of the innovation processes. This paper analyses conceptually and contextually the TRL scale also used in acquisitions of military equipment, in order to emphasize the necessity of the scale so that it corresponds to the purpose of the European decision makers.