(FORTUNE Magazine) – Long before most chief executives knew what corporate restructuring was, Jack Welch was doing it. He jolted GE to life in 1981, after being named its eighth and, at 45, youngest chairman. Since then he has eliminated 100,000 jobs, removed entire echelons from the hierarchy, and shifted assets from mature manufacturing businesses into fast-growing high-technology and service operations. A year ago he picked up RCA Corp. for $6.4 billion, in history's largest nonoil acquisition. Today his conglomerate crackles with the kind of electricity that excites investors. GE's stock trades around $56, 228% higher than it did when Welch took over. Welch grew up in working-class Salem, Massachusetts, the only son of a railroad conductor. ''I was an Irish altar boy who went to Mass every morning ; because my mother sat in the front row,'' he recalls. She was a proud, strong- willed housewife who infused Welch with ambition and self-confidence, telling him that his stammer, which persists today, was not a defect but merely a sign that his mind raced faster than he could talk. He never dreamed of becoming a big businessman. After earning a doctorate in chemical engineering at the University of Illinois, Welch went to work for GE in Pittsfield, a town in the Berkshire mountains of western Massachusetts. He transformed a struggling plastics business into a $400-million-a-year powerhouse and emerged as a brilliant, sometimes abrasive leader with a voracious appetite for detail. Intolerant even of GE's vaunted bureaucracy, Welch rose outside it. He refused to uproot his family, and the company, instead of insisting that he transfer, simply added units to his Pittsfield operation. He eventually won the chairmanship in a six-way race. While keeping an iron grip on the allocation of GE's capital, Welch encourages heads of the company's 20 major businesses to make most other decisions. He despises managers who swaddle themselves with staffs and hoard information. ''The old close-to-the-vest corporate bureaucrat is now the abnormal guy at GE,'' Welch says. At gatherings of top managers, he makes time for leisurely coffee breaks and dinners so executives can swap advice and make deals informally.

Longer on substance than on style, Welch often gropes for phrases and leaves ideas dangling awkwardly. Yet he has made his vision clear from top to bottom at GE. In place of what many employees had come to expect -- a job for life -- Welch offers a pragmatic 1980s-style deal: ''A company owes its people a fair, open atmosphere where they have the chance to do their best and win. Their job is to take advantage of this, to grow in it, change in it, and talk about tomorrow instead of yesterday.''