A key governance mechanism in the business silo stage of enterprise IT architecture is:

In the business silo stage of enterprise IT architecture, a key governance mechanism is the business case. This is crucial because a business case provides a detailed justification for a particular project or initiative, outlining its value in terms of cost, benefits, risks, and alignment with business goals. In environments where departments often function independently, having a solid business case helps to ensure that investments in IT align with the overarching business strategy and directly address departmental needs or solve specific problems.

The emphasis on the business case reflects the need for justification and evaluation of IT initiatives, particularly when resources are constrained, and departments might prioritize their internal goals over collaborative ones. This mechanism encourages departments to consider the broader impacts of their decisions and fosters accountability in how IT supports business objectives.

Other mechanisms like IT standards committees and enterprise-wide process owners play important roles in more integrated or aligned architectures but are less emphasized in the silo stage, where individual business units may operate more autonomously and focus primarily on their own governance and outcomes.