Tesco store managers are being encouraged to spend more time on the shop floor following the rollout of handheld terminals.
The digital assistants mean managers stay connected to email and other IT applications rather than having to keep returning to their desks.
They also have built-in barcode scanners that enable instant price and stock checks, reports on category and item performance as well as reviewing overall store sales.
Tesco project manager Simon Hick said that giving managers the use of email alone on the shop floor would free up seven to eight hours a week.
Sainsbury, meanwhile, is to roll out its handheld Retek Store System after Christmas. The kit allows staff to check stock room availability levels and pricing while on the shop floor. More than half of its stores now have at least one RSS device.