It was a dream job, the type of assignment that could make or break the career of an ambitious executive with an eye toward the top. “It was my first big promotion,” says Bernard J. Tyson, the 57-year-old CEO of Kaiser Permanente, a health care company with nearly $60 billion in annual revenue. The year was 1992, and Tyson, then in his early thirties, had been named administrator of one of Kaiser’s newest hospitals, in Santa Rosa, Calif. “Everyone knew this was the hospital to lead,” he says.