This paper explores how the introduction of CASE tools in systems development changes the social relations among project team members. An investigation into the role of CASE tools on projects found structural changes due to modification of the systems development division of labor and shifts in patterns of dependency among project team coalitions. These changes triggered a polarization among the system developers which was evinced in acts of coercion and rebellion, the display of territorialism, resentment, and stereotyping, as well as the enactment of subcultures. These findings are interpreted within a broader social theoretic framework, and their implications for research and practice are discussed.