That now-infamous overhaul, under then-CEO and former Apple retail guru Ron Johnson, sought to reposition Penney as a flashier retailer with fancier merchandise. But it backfired: Customers fled, sales tumbled by almost a third, and Penney was crippled financially. Three years ago the board brought back Mike Ullman, the CEO it had unceremoniously chased out in favor of Johnson, to stop the U.S.S. Penney from sinking. And last summer he handed the reins to Ellison—an executive the opposite of flashy. ... It’s fitting that Ellison, a lifelong musician, plays electric bass, an instrument that rarely gets a flashy solo but without which no band can click. He made his reputation in retail at Home Depot, helping engineer that chain’s turnaround by focusing on unsexy but primordial things like the supply chain and the integration of stores and e-commerce. He’s a data devotee who grounds every decision in information—including that seemingly intuitive shoe move. ... The trees look nice, but the forest is daunting. Penney’s sales, an estimated $12.6 billion for the just-completed year, are still down 37% from their 2006 peak. Its nascent recovery, part of its fourth turnaround effort since 2000, hasn’t swayed Wall Street—its stock trades close to a 35-year low. In the long term, the problem isn’t just that Penney has been dysfunctional; it’s also that Penney is a department store, a practitioner of a business model under siege.