Innovation, which is acknowledged as a key factor for the development of companies, may be too delicate to become a success for companies. Uncertainty related to value creation is often an important dissuasive reason. This is particularly the case for high-tech small and medium enterprises (SMEs). Indeed, they often have scarce human and financial resources which handicap them in accessing new knowledge. This weakness can be crucial at a given stage of the innovation development because SMEs loosely represent processes and knowledge. The second aspect we consider here is the type of innovation developed: a disruptive technological innovation. It presents a high technological uncertainty and involves a market discontinuity. As a result, it is inherently characterized by a lack of knowledge regarding the technology and the market. This context leads to establish that one of the most important challenges in technological disruptive innovation projects in SMEs is the identification and access to critical knowledge. The literature review describes innovation processes as a more or less complex succession of activities and decisions. But the decision-making micro-stages, whose quality depends on the ability of identifying and accessing specific and critical knowledge, is one weak point of high-tech SMEs. We propose here a model to increase efficiency of critical decisions in disruptive innovation projects under the following hypothesis: critical decision-making in a disruptive technological innovation project in a SME is easier, more rational and robust when decision-makers know its impacts in term of value creation and risks associated to all decision alternatives. This model is tested within a project on two decisions assessed as critical; one of them is detailed here. The results of these two experimentations validate our hypothesis. We realized interviews on feedbacks from our case study that demonstrate that the use of this method was very helpful to inform and facilitate the work of decision makers. Our implementation of a formalized decision process enables robust decision-making without hindering the flexibility of the innovation process of the SME.