The move was just the latest step in what Walmart (WMT) U.S. operations chief Judith McKenna acknowledged is the retailer’s attempt to get back to the core purpose of what the company was built on.

“You will get cynicism, and the only way to break through is keep showing people and take actions,” she said at a panel at Fortune’s Most Powerful Women summit on Monday. “You might not get it right all the time, but you have to be genuine in your intent.”

McKenna stressed that purpose and profit must go hand in hand and that clearly articulating a mission is essential in motivating a business that has 1.2 million employees. Ask any one of them why Walmart exists, she said, and they should tell you, “We save people money so they can live better.”

“When you’re of that scale, you have to have a common purpose,” she said, “and everyone has to understand it and business decisions have to be made against it.”

Sometimes it’s the little things that move the needle forward, McKenna said. She gave the example of how Walmart stopped playing the same CD over and over in stores after employees told management it was driving them crazy.

McKenna noted that the hardest group to reach is members of middle management and that she’s been trying to find a better way to communicate with them. She has recently met with 700 store managers over the course of four days in 10 cities.

“If we can start to move store managers in terms of how they believe and what they feel, that is the fastest way to get to all of the associates,” McKenna said.

But she noted that Walmart is also being clearer now not just with employees but with all its stakeholders, including its vendors. “Consistency of message through everything we do will help us stay on track going forward,” she said.

She stressed how important it is to sweat out every word of a purpose statement, noting that the “we” and the “they” in “We save people so they can live better” slogan are very intentional. “It’s a painful process,” she said, “but it’s worth it.”