Wal-Mart director Jack Shewmaker – the retailer’s former chief financial officer and founder Sam Walton’s right-hand man – has warned that it must accelerate change to safeguard success.

He said that the stores giant, along with other retailers, faces “really big challenges”, as retailing and the wider world are transformed.

“The world is changing. Wal-Mart has to change, but I’m not sure it’s changing fast enough,” said Shewmaker.

Speaking at last week’s World Retail Congress, he warned that one of the biggest challenges facing Wal-Mart was to avoid “doing what Sam Walton never did – underestimating the competition”.

He said: “When we get in that position, we undervalue new concepts from a new field of competitors. You need to do what Sam did and look at what others do better than you.”

“I’m not representing Wal-Mart as a spokesman, although I’m a director,” he added.

Shewmaker also voiced concern about Wal-Mart’s and other retailers’ “failure to succinctly meet customers’ needs in core markets” and the threat posed by failing to reinvest in core business because of “getting caught up in growth mode”.

He flagged up the need to communicate effectively with all stakeholders, from suppliers to customers, staff and investors. “Don’t get overly focused on one segment so you slight another. Wal-Mart has been guilty of that over the years,” said Shewmaker.

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