In this article, the author offers an analysis of psychoanalytic application, defined as the breaking of new conceptual ground in some field of knowledge whereby the new idea is conceived, and later articulated, with the aid of reference to analogous phenomena in psychoanalysis. It requires apt analogy based on competent understanding of the applied field and of psychoanalysis. Only when the relevant differences between the applied and psychoanalytic fields are grasped can the extent of certain parallels emerge. The thinking by analogy that comprises psychoanalytic application may be intuitive and implicit, but should be susceptible of explicit theoretical elaboration that specifies, precisely, the point(s) of correspondence between psychoanalysis and the applied field in relation to a precise specification of their relevant differences. Applied psychotherapy at the interface of the internal and external worlds (historically rooted in casework) is employed as a model. By analogy with Donnet's concept of the analytic site, the author proposes the concept of the psychodynamic (case)work site, and elaborates it for that applied field in order to elucidate the proposed principles of psychoanalytic application.