From the viewpoint of modeling of coated film drying, research papers by the author and colleagues, published mainly in Kagaku Kogaku Ronbunshu, on binder segregation estimation, the temperature-change method and a drying characteristic model are reviewed and future prospects are discussed under the keyword of "correlation model." A correlation model by the lumped parameter system was recently proposed that aimed to provide rapid feedback to production of research results into complicated phenomena of coated film drying. Here, "correlation" means the interrelationships among variables in the phenomena on the basis of mass-and energy-balance equations. In the correlation model, establishment of an appropriate balance domain obviates the need for parts (a) or all (b) of transport properties or transport mechanisms (c), in contrast to the prediction model, in which transport mechanisms and properties are all indispensable for simulation of the phenomena. The correlation model may allow research results to be fed back rapidly to production. This review discusses the temperature-change method to estimate drying rate by using the temperature history of wet material during drying as an example of (c), and the method for estimation of binder segregation within dried material by using drying rate history during drying as examples of (a) and (b). Both proposed methods are based on models of the lumped parameter system. Combination of the two methods may allow estimation of binder segregation by using material temperature history.