Consultant Deborah Lovich could be accomplishing the management feat of the mobile era. She's convinced hundreds of agile-thumbed, on-at-all-hours colleagues to put down their smart phones and stop working or checking e-mail all evening long.

True, the break happens only once a week. But Boston Consulting Group's "predictable time off" experiment has been a hit. Since it was widely introduced in 2009, more than 900 internal teams have taken part, and the program has become standard practice at most BCG offices in North America and Europe.

Lovich, head of BCG staff in Boston, developed the program with Harvard Business School professor Leslie Perlow, who in studies begun in 2005 found that BCG consultants felt burnout not only because of long hours, but because they could never predict or control when they might have a break from work.

The problem was BlackBerrys and other mobile devices. BCG workers felt pressure to respond to e-mails from a boss or client right away, even when it wasn't urgent. Responding to one message could set off a chain reaction of e-mails lasting until bedtime.