A device for determining whether a defect of a component is determinable based on results of predefined diagnostic options, including: storing, in a matrix, parameters which, for each combination of one component defect and one diagnosis result, provide a measure of whether the respective defect is possible for the respective diagnosis result, the matrix rows being assigned to one of the diagnosis results, the matrix columns being assigned to one of the defects; selecting at least two matrix rows which, for a diagnosis result consistent with the defect to be identified, include a parameter greater than a predefined first limiting value; calculating a result vector by the element-wise multiplication of the selected matrix rows; and determining whether the result vector includes at least one element not smaller than a predefined second limiting value, the result vector elements, which are smaller, not being greater than a predefined third limiting value.