Lee Kun-hee, the man who built the most successful, most admired and most feared business in Asia — a $288 billion behemoth that is among the most profitable in the world — had a message for his employees this year: You must do better.

At other companies, congratulations might have been in order. His companies were headed to another extraordinary year. But this was Samsung, the South Korean industrial group that Mr. Lee, an elfin man with a stubborn will, transformed from a second-rate maker of household appliances into a conglomerate with a flagship electronics business that has left most rivals eating its silicon dust. There would be no pat on the back for Samsung’s 470,000 employees. Instead, in June, he sent a companywide email sternly urging them to raise their game.

“As we move forward, we must resist complacency and thoughts of being good enough, as these will prevent us from becoming better,” Mr. Lee, who is 71, wrote. Samsung’s management, he said, “must start anew to reach loftier goals and ideals.”

Two decades earlier, having taken over the company from his father, Mr. Lee met with dozens of his executives and gave them a similar order, one that remains embedded in company lore: “Change everything but your wife and children.”