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A set \( S \subset V \) of vertices in a graph \( G = (V, E) \) is called open irredundant if for every vertex \( v \in S \) there exists a vertex \( w \in V \setminus S \) such that \( w \) is adjacent to \( v \) but to no other vertex in \( S \). The upper open irredundance number \( OIR(G) \) equals the maximum cardinality of an open irredundant set in \( G \). A real-valued function \( g: V \to [0,1] \) is called open irredundant if for every vertex \( v \in V \), \( g(v) > 0 \) implies there exists a vertex \( w \) adjacent to \( v \) such that \( g(N[w]) = 1 \). An open irredundant function \( g \) is maximal if there does not exist an open irredundant function \( h \) such that \( g \neq h \) and \( g(v) \leq h(v) \), for every \( v \in V \). The fractional upper open irredundance number equals \( OIR_f(G) = \sup\{|g|: g \text{ is an open irredundant function on } G\} \). In this paper we prove that for any graph \( G \), \( OIR(G) = OIR_f(G) \).