Productivity vs. cost: What you must consider before cutting the cord and mobilizing Your workforce
As technology makes it possible for workers on the move to be connected to their files, data and clients at anytime from anywhere, there is a greater expectation for worker productivity. But unless you take into account issues such as mobile and Wi-Fi network performance, service provider data limits, stress of mobile devices on server infrastructure, differences in device hardware and software, and mobile security, you may have a "mobile" workforce, but one that is less productive and more expensive than an in-office workforce.
Story added 10. September 2012, content source with full text you can find at link above.