In deciding the chances of failure of a design, two types of information are available: objective and subjective. In dealing with objective information in the form of countable data, unbiased probability distributions of loading and structural capacity are obtained by employing the principle of maximum entropy. Subjective information is considered in a linguistic form and requires a transformation from the verbal to the numerical. This is attained by the use of fuzzy set theory. The fuzzy calculus is then employed to fuzzify the objective probability in light of the subjective insight. The result is a fuzzy safety measure that expresses the confidence in the objective probability and also in other, larger values of the probability of failure. In this way objective, numerical, frequency type information can be augmented by professional insight and experience.