About half of the world's companies will enact BYOD (bring your own device) programs by 2017 and will no longer provide computing devices to employees, a new Gartner report predicts.

Ultimately, only 15 percent of companies will never move to a BYOD model, while 40 percent will offer a choice between BYOD and employer-provided devices, according to the report by Gartner analyst David Willis, which was announced Wednesday.

While mobile computing helps make on-the-go workers more productive, the average cost of more than US$600 per employee per year for company-provided devices has been difficult for many to shoulder, Willis wrote. This along with other factors, such as increased employee satisfaction, has helped drive the BYOD movement, he added.

So far, BYOD adoption is most common in companies with between $500 million and $5 billion in revenue, but there are significant differences according to geography, said Gartner. The U.S. adoption rate is double that of Europe, but the highest rate is in India, China and Brazil, according to the report.

Still, while most IT executives surveyed by Gartner think well of BYOD, only 22 percent "believe they have made a strong business case," according to the report.

Mobility projects "are often exploratory and may not have a clearly defined and quantifiable goal," the report adds. "While there are many mobile applications with a provable return on investment, stumbling onto a breakthrough does not seem like the right strategy."

Meanwhile, although BYOD programs allow employees to use their preferred device, that doesn't mean their employers don't incur any costs.

"Workers with an essential need to use a mobile device in their business expect to be compensated for its use, just as companies typically reimburse for the incremental cost of mileage and travel expenses," Willis wrote.

However, there are currently no standard practices for BYOD reimbursement, according to the report. Only about half of today's BYOD programs provide some reimbursement, usually for the service plan associated with an employee's device, and just 2 percent cover all costs, the report states.

Still, "no mobile worker is free," Willis wrote. "More employees and more devices mean more security and management tool costs, more application licenses, more potential problems for an overtaxed help desk to deal with, and more confusion."

Costs associated with that overhead "can easily exceed $100 per worker per year today," he added. That figure will hit $300 by 2016," largely due to license fees for mobile apps."

Chris Kanaracus covers enterprise software and general technology breaking news for The IDG News Service. Chris' email address is Chris_Kanaracus@idg.com