Australian supermarket operator Woolworths needs to improve efficiencies if it is to progress on the global stage, according to a director of US retail giant Wal-Mart. "As lean as they are, I keep telling them they could be even better and that doesn't mean you take people away from the checkouts at the store and the people out of the meat department, it means that the efficiencies of the process can be improved," Wal-Mart's Jack Shewmaker told Channel Nine in Australia.