Culture

The apparent simplicity of the three-legged stool is deceptive. It means that an outsourced project takes just as much time and effort from IT and business management as an in-house project. And in one area -- personnel -- it takes even more.

Marriott typically chooses the outsourcer through a comprehensive, competitive request for proposals (RFP) process. Among the most important factors it considers is cultural fit. "You have to pick the partner that is culturally aligned with your organization," Cullen says.

That goes for the individuals as well as the company as a whole. "We approve all the team leads, and we interview all the key people," Melnick says. "Although everyone they may submit may be competent, the chemistry is also important."

The result of this attention to personnel upfront is long-term relationships with individuals that sometimes transcend specific projects. For example, as an Accenture employee, Shelton has been working with Marriott for years. "We get a really good cultural fit, and we get continuity as well because we're not retraining people," Melnick explains.