We can "read" eq. (1) as follows. The robustness formula_67 of decision vector formula_18 is the greatest value of the horizon of uncertainty formula_1 for which specified minimal requirements are "always" satisfied. formula_67 expresses robustness — the degree of resistance to uncertainty and immunity against failure — so a large value of formula_67 is desirable. Robustness is defined as a "worst-case" scenario up to the horizon of uncertainty: how large can the horizon of uncertainty be and still, even in the worst case, achieve the critical level of outcome?