The functional analysis procedures described in the seminal Iwata et al. (1982/1994) study are prominent in the applied behavior analytic literature, having been replicated hundreds of times over the past 30 years (Beavers, Iwata, & Lerman, 2013; Hanley, McCord, Iwata, 2003). However, the extent to which particular components of this functional analysis model have become more or less prominent over time is not clear from these literature reviews. We therefore conducted a review of the functional analysis literature between the years of 1965 and 2016 to determine the trends in the usage of particular components over time and to determine if the published literature reflects a standardization of the manner in which functional analyses of problem behavior are conducted. Furthermore, we discuss whether or not this standardization of a functional analysis model is currently necessary.