An evaluation is performed for a device, an application and/or a method, in particular a method for establishing a technical system such as a power plant for instance, the assessment being carried out on the basis of costs for risks. In accordance with the method, the costs for specific risks are to be assessed. A risk costs interval is to be determined, which contains the actual risk costs with high probability. This is achieved by a regression of intuitive assignments to a straight line by an indirect linear regression by a non-linear regression in an intermediate diagram.