ITIL outsourcing rarely, if ever, works for several reasons but mainly because vendors have little or no resources with the requisite knowledge and experience to successfully deliver what the customer needs. Further, the cost constraints of outsourcing agreements lead only to vendors acquiring low-cost, barely qualified resources to meet staffing requirements. After all, the outsourcers is in business to make a profit.
IT Managers would do well to remember that profit comes from keeping costs down. One of the biggest overhead costs for IT outsourcers is labor.
High quality does not equal low cost.