Bookend the Future

Bookend the Future

Instead of relying on a single “point” forecast, consider a range of plausible outcomes and prepare for both bad results and unexpected success. In the book’s investment example, Penstock backed Coinstar after comparing its potential upside with its downside. One way to widen an overly narrow range is to ask “What’s an outcome so good/bad that there’s only a 10% chance of it being exceeded?” The question prompts a more explicit estimate; it does not guarantee an accurate one.

Identify the variables that matter, describe plausible outcomes at both ends of the range, and decide how you would respond. Include the middle, too: the purpose is to improve preparation, rather than to predict only extremes.

For the lower bookend, conduct a premortem: “It’s a year from now. Our decision has failed utterly. Why?” The book describes the 100,000 Homes Campaign using this approach to identify and address a legal vulnerability.

For the upper bookend, run a preparade: “It’s a year from now. We’re heroes. Will we be ready for success?” The Softsoap example describes its producer securing plastic pumps for 18 to 24 months in preparation for a national launch.

A safety factor adds capacity beyond the expected requirement. The book’s elevator-cable illustration uses a factor of 11; the appropriate margin in any real design depends on its requirements. Project schedules can likewise include time for delays, though a buffer cannot cover every possible failure.

Preparation can also change expectations. A “realistic job preview” shows the difficult parts of a role before someone accepts it, “vaccinating” the new hire against some avoidable disappointment. Sandra’s rehearsal of a request for a raise serves a similar purpose: she plans how to respond to awkward moments before entering the conversation.