When examining both the technical and commercial feasibility of the project, reasonable assumptions must be used in the initial concept phase. The evaluation of the technical and economic success must be carried out with manageable effort, quickly and safely within defined tolerances. Reasonable assumptions can only be made by someone who is able to comprehensively design and evaluate the project from a technical and economic point of view based on the task at hand, even if the requirements are not completely defined. And this is exactly the point. Due to my experience and competence both in technical terms and in estimating the associated investment, I am able to create a reliable technical and commercial project concept in short term, even if only a few key points are known.