In an uncertain economic decision environment, an expert's knowledge about the defender's remaining life and its cash now information usually consist of a lot of vagueness instead of randomness. To describe a planning horizon which may be implicitly forecasted from past incomplete information, linguistic description like 'approximately between 10 and 14 years' is often used. A fuzzy replacement analysis for a defender is examined in the paper. The life of the defender is given by a membership function that is an intersection of the membership functions regarding the physical impairment of the defender, its obsolescence, and external economic conditions. A fuzzy economic analysis for replacement decision is also given.