Sergio Marchionne Sweated Small Stuff and Slashed Bureaucracy at Fiat Chrysler

CEO combined European design flair with North American devotion to shareholder returns

One day near the end of 2010, Sergio Marchionne received a message on one of his six smartphones: A colleague updated him on efforts to fix a door-latch defect on a new version of the Dodge Charger.

“I am getting updates every couple of hours on the bloody door handle,” he told a Wall Street Journal reporter.

Was this a wise use of time for...