HBR posts (comics found at the link):
Adams started cartooning while working at Pacific Bell Telephone Company (later acquired by AT&T), after being repeatedly passed over for promotion. “The day you realize that your efforts and rewards are not related, it really frees up your calendar,” he says in his book, “I had time for hobbies.” Some of the first Dilbert doodles appeared on the whiteboard in Adams’ cube, and it was one of his coworkers who suggested the name of the title character.
In the early days of Dilbert – March 1990, when the strip appeared only in a few newspapers – Adams included a direct quote from a memo written by the then-VP of engineering at Pacific Bell.
Inevitably, an employee of the VP mocked in the strip shared copies with his staff. But because it would be a strike to morale to fire a popular employee for making jokes, Adams insists that his bosses opted for a different management approach.