Ed Catmull is not who you think of when you hear PIXAR (John Lasseter and Brad Bird are probably the first two). But he has been there through their successes and has some theories as to why they’re the only studio that hasn’t had a flop:

When a business scores a string of triumphs or attains a dominant market position, its people often stop trying to improve. Catmull is determined that Pixar will be different. Toward that end, he personally ensures that post mortems of productions are taken seriously. And he regularly reminds employees–especially young new hires–that Pixar has made plenty of mistakes in the past and still doesn’t have it all figured out.

Pixar's Collective Genius – Harvard Business Online's HBR Editors' Blog