In the last decade ordinal optimization (OO) has been successfully applied in many stochastic simulation-based optimization problems (SP) and deterministic complex problems (DCP). Although the application of OO in the SP has been justified theoretically, the application in the DCP lacks similar analysis. In this paper, we show the equivalence between OO in the DCP and in the SP, which justifies the application of OO in the DCP. Keywords Ordinal optimization . Equivalence . Deterministic complex problems . Stochastic simulation problems