From your profile I guess your question is not really about the technicalities or the features of SEM and how it could be helpful in the context of SCM. I see it more from a conceptual perspective. That is, what factors related to IT may affect other factors related to SCM and that these relationships could be examined and analyzed with SEM, am I right? If yes, then this goes back to the main research aim and the formulation of the hypotheses.
Some factors related to IT that were studied with heavy use of SEM are: IT adoption, IT innovation, Diffusion of innovation, IT strategy among others. From an SCM viewpoint, factors like SCM strategy, integration (cross-functional and cross-organization), information sharing, performance (of SCM and organization) etc.. are all factors that were studied in the literature using methodologies involving SEM.