McDonald's on Thursday announced changes that could reshape the diner's experience, saying that it would expand its digital self-serve ordering stations and table service to all of its 14,000 American restaurants.The company said that once people order at one of the stations sleek, vertical touchscreens they will get a digital location device and can take a seat. When their burgers and fries are ready, the technology will guide a server to the table to deliver the food with a big smile and a thank you."Typically, the majority of our crew is behind the counter, and that counter literally has been a barrier between our crew and the customer," Steve Easterbrook, chief executive of McDonald's, said at an event Thursday in a newly renovated and outfitted McDonald's on Chambers Street in New York.Customers will still be able to order food the old-fashioned way, at the counter. But the move to self-order systems and table service is one way to address one of the biggest problems the company's restaurants have faced in recent years: slower food delivery to customers, caused by more items on the menu. The thinking is that customers will be more willing to wait if they are sitting at a table instead of waiting at a counter.But it also raises some questions for the company: What does it mean for workers, and is the chain up for a change this big?Easterbrook said the new system would not reduce costs. But it would mean that workers might have slightly different jobs."We've not cutting crew; we're redeploying them," he said.McDonald's has tested the order system in 500 revamped restaurants, or what it calls its "just-for-you experience," in New York, Florida and Southern California and is now introducing them in Washington, San Francisco, Seattle, Boston and Chicago. Around the globe, the new program is in some 2,600 McDonald's restaurants.Easterbrook and other company executives said some 44,000 customers have been served at tables using the new system in the United States. Families and groups have been the biggest users, but the company expects the screens to attract customers of all kinds as they become more widespread. The self-serve stations, the company says, make it easier to customize an order."This is a huge opportunity for us to personalize and elevate the experience of our customers in the United States," said Chris Kempczinski, the new president of U.S. operations.Many of the company's customers, though, do not enter the restaurant. About 60 to 70 percent of sales come from its drive-thru lanes."A lot of customers are never going to see this technology," Dick Adams, a restaurant consultant, said. "It's just not going to be that big a factor for most franchisees outside big cities."The company also announced that it would roll out a mobile order-and-pay system that would also change the way customers get their orders, including customers ordering from their cars.Much of what is coming to the United States has been tried in markets like Canada, Australia and Britain, where roughly one-quarter of transactions are done on in-store screens.How quickly the restaurants change remains to be seen. The vast majority of McDonald's locations are owned by franchisees, and they will be responsible for paying for the changes. Equipment and installation of the eight order screens at the event Thursday, at a location in the Tribeca neighborhood of New York, cost $56,000, said Terri Hickey, a spokeswoman for McDonald's. The costs for a store with lower sales volume would probably be about $28,000.Franchisees may be loath to make such investments at a time when restaurant sales are lackluster at best same-store sales in McDonald's U.S. restaurants rose a paltry 1.3 percent in the third quarter of this year.Many of the company's stores in Britain have undergone such a reboot, and in a video, Paul Pomroy, chief executive of the business in Britain, said the investment was worth it."The customer's perception of the quality of the food has changed," Pomroy said. "A Big Mac tastes better in a reimaged restaurant, it just does."