Bharti Airtel outsourced the building and maintenance of its telecom network to vendors like Ericsson, Nokia, and Siemens in 2004. It also signed a 10-year partnership with IBM to outsource its IT network and operations based on a percentage of Bharti's revenues. This allowed Bharti to focus on its core operations while transferring investment risks and costs to vendors. However, outsourcing brought challenges around material imports, employee transfers between companies, and ensuring vendors had sufficient capacity for Bharti's growth. Overall, outsourcing helped lower Bharti's capital and resource costs while diversifying risks across multiple vendors.