Tag Archives: benoit-mandelbrot

Why Software Development Estimation is Hard: Sea Lions, and Coastal Paths

Among the many valid responses to the Quora question of why software development task estimations are often off by a factor of 2–3, Michael Wolfe, CEO of Pipewise, describes exactly why this is without once mentioning ‘software’ or ‘project’.

Instead, Wolfe eloquently provides undoubtedly the best analogy I’ve ever heard for explaining the difficulty in providing estimates for software projects: a couple of friends planning a coastal hike from San Francisco to Los Angeles and starting their journey.

Their friends are waiting in LA, phone calls have already been made pushing the date back…

Man, this is slow going! Sand, water, stairs, creeks, angry sea lions! We are walking at most 2 miles per hour, half as fast as we wanted. We can either start walking 20 hours per day, or we can push our friends out another week. OK, let’s split the difference: we’ll walk 12 hours per day and push our friends out til the following weekend. We call them and delay dinner until the following Sunday. They are a little peeved but say OK, we’ll see you then. […]

We get up the next morning, bandage up our feet and get going. We turn a corner. Shit! What’s this?

Goddamn map doesn’t show this shit!. We have to walk 3 miles inland, around some fenced-off, federally-protected land, get lost twice, then make it back to the coast around noon. Most of the day gone for one mile of progress. OK, we are *not* calling our friends to push back again. We walk until midnight to try to catch up and get back on schedule.

Of course, this isn’t exactly a new analogy: it’s applying the ideas behind Benoît Mandelbrot’s paper, How Long Is the Coast of Britain?, published back in 1967, to software estimation. Still, it works perfectly.

If you like Wolfe’s writing style and want to read more, he runs a blog called Dear Founder.

Update: And of course, there’s always O.P.C.