Phil Sayer, Forrester Research, writes a helpful article and offers insights from their findings. From CIO.com:
Forester found that I&O professionals should:
Retain knowledge and expertise. Consider business, technical, and governance criteria when identifying key skills and resources required for rapid response to unplanned business needs as well as control over future strategy and architecture.
Manage the outsourcing relationship. Clear, continuous communication of business needs and expectations between the internal IT staff and the external provider helps establish and manage realistic expectations all around. Regular service and contract reviews are a vital part of this process.
Monitor and manage the supplier. IT organizations need dedicated internal resources to monitor service levels, manage change, escalate late trouble tickets, and hold regular service meetings. Attention to detail is essential to obtain good service from the supplier.
Maintain the balance of control and initiative. An adequately staffed and knowledgeable internal IT organization signals independence and helps drive external providers to deliver service to the contracted quality level and to demonstrate value.