“…When the terms of the temperatures of the hot fluid entering the heat exchangers, t 11 , t 21 , and t 31 , are rewritten in terms of T 1 and T 2 , and the resultant expressions in the constraints defined by eq are replaced, the problem now has five decision variables, namely, the area of the heat exchangers, A 1 , A 2 , and A 3 , and temperatures T 1 and T 2 . Thus, the new constraints of the problem are as follows: For reliability-based optimization, Lobato et al suggest that model uncertainties are associated with the constant terms in the inequalities, so that they are treated as independent normal random variables X = ( X 1 , ..., X 8 ), with the mean equal to the constants in eqs 23 and the standard deviation as in Table . In this case, the equivalent inequalities of the deterministic problem, given by eqs 23, can be transformed into probabilistic constraints.…”