This post was referred to in one of Melissa Perry’s course on market sizing and I loved how it refers to DEC vs Dell.
And this one as well via HBR on market sizing which has a cool tryptic.
Over-specialization is at the root cause of all three errors. Anyone with expertise has confirmation bias risk. Few people have expertise in multiple disciplines necessary. To correctly size the prize, you need three lenses — a microscope (e.g., consumer passion, activation, super-geos), a telescope (industry breadth and broad strategy expertise), and a mirror (confirmation bias). To avoid confirmation bias, you need a breadth of industry experience and likely strong strategy expertise. To solve for the second error, you need extensive expertise with consumers. To solve for the third error, you need expertise in execution and activation. Consultants and bankers, who spend a lot of time doing size the prize analysis, have relatively little experience with consumers or execution, which is why many of these analyses turn out wrong.HBR