The nature of the relationship between the IT function and the Lines of Business shapes the policies for managing business services. In particular, the selection of lines of authority and and financial model for the ITfunction dictates which business objectives drive the management of competing business demands for shared IT resources and services. This paper proposes to model business service management policies in a three-layer hierarchy and studies the impact of IT Governance models on those policies. A software embodiment for the management of those policies is also highlighted.