Gartner defines multisourcing as the use of three or more service providers (which may include internal resources) to deliver key IT services and IT-enabled business services to a company under a continuous service arrangement.
Without a strategy (for multisourcing), companies don’t make necessary investments in organization and governance, which results in inadequate structures, processes and tools for effectivly managing this complex sourcing model.
The key to the multisourced environment is outsourcing key IT-services on a continuous basis (vs. discrete project-based services).
Best services and solutions delivered at a competitive price
Ability to better align services to business strategy
Greater agility and precision
Source: Christopher Ambrose, Lorrie Scardino: Multisourcing is the New Norm for Sourcing IT Services, COM-23-1233, 2004-07-01
Further reading: Sourcing Strategies: Relationship Models and Case Studies, R-18-9925, 2003-02-07