Decline and Fall
What are the early indicators of decline? The moment you begin to doubt the facts of your data and debate its ramifications, you're already in "level 2" of decline. Level 5 is capitulation to irrelevance -- or death.
Collins studied 40 companies that have fallen from great to good, or never became great. He asks, what is the signature of mediocrity? He describes the extraordinary success of Southwest, which actually, literally, copied the business model of another airline. They have been one of the most successful publicly-traded companies and yet they did not innovate anything. Today, Southwest is still around and profitable, while the airline they copied is long gone. Why? The other airline got spooked by all the changes in its operating environment and didn't stick to its plan. Southwest never changed.
Mediocrity is not an unwillingness to change. The signature of mediocrity is chronic inconsistency.