Use a bid process: The big three will lecture you on their individual differences, and when I interviewed at the firms, I was obsessed about what made them different.

FORBES: What Value Do Consulting Firms Like McKinsey, Bain, Et Al. Really Add To An Operation?

Black is one of three speakers talking about the subject this week at a lecture entitled, "From Chemistry to Catwalk, " to be held at the Royal Institution of Great Britain.

CNN: From chemistry to catwalk