Compiled By Peter Strozniak Pittsburgh-based Alcoa Inc., the world's largest manufacturer of aluminum, plans to reduce costs by $1 billion over the next three years. The new goal announced this week by Alain Belda, Alcoa's CEO and chairman, follows the company's $1.1 billion in cost reductions between 1998 and 2000. "The continual focus of Alcoa's employees worldwide on the productivity of assets and the elimination of waste is the heart of the company's operating discipline, applicable in all economic environments," Belda says. "This is not a people-reduction initiative." Alcoa reported record net income of $1.4 billion, or $1.80 a share, in 2000, up from $1 billion, or $1.41 a share a year ago.