Abstract: The present disclosure is directed to the methods for identifying a combined corrosion inhibitor formulation comprising at least a first and second corrosion inhibitor formulation for inhibiting corrosion in various substrates, for example in metal substrates. The present disclosure is also directed to compositions for inhibiting corrosion comprising a combined corrosion inhibitor formulation each independently selected from organic heterocyclic compounds and metal salts, metal anions, metal complexes, or any combinations thereof selected from rare earth, alkali earth and transition metals.