News: 0176557133

  ARM Give a man a fire and he's warm for a day, but set fire to him and he's warm for the rest of his life (Terry Pratchett, Jingo)

'My Washing Machine Refreshed My Thinking on Software Effort Estimation' (cosive.com)

(Thursday February 27, 2025 @11:40AM (msmash) from the unexpected-epiphanies dept.)


What Chris Horsley expected to be a 10-minute washing machine installation [1]stretched to four hours and required five trips to the hardware store . The CTO of security consultancy firm documented how unexpected obstacles -- drilling through shelves, replacing incompatible hoses, and removing hidden caps -- derailed his timeline.

Horsley draws a direct parallel to software development, where estimation regularly fails despite experience. "While 90% of the project will be the same, there's going to be one critical difference between the last 5 projects and this project that seemed trivial at the time of estimation but will throw off our whole schedule," he writes in a blog.

These disruptions often appear as unmaintained frameworks, obsolete development tools, or incompatible infrastructure components that weren't visible during planning. The software development environment changes rapidly, creating what Horsley describes as "unknown unknowns." Despite thorough requirements gathering, developers inevitably encounter unanticipated blockers, transforming familiar-looking tasks into complex challenges.



[1] https://www.cosive.com/blog/my-washing-machine-refreshed-my-thinking-on-software-effort-estimation



Three trips (Score:1)

by flyingfsck ( 986395 )

Any DIY plumbing job requires at least three trips to the HW store.

Re: (Score:2)

by CWCheese ( 729272 )

sometimes four or five

"unknown unknowns" (Score:2)

by v1 ( 525388 )

I just refer to those as "ambushes" or "traps"

If it's just an issue you hadn't anticipated but that can be easily adjusted for once discovered, it's a trap.

If it's something you didn't anticipate AND is going to require significant accommodations in time and/or money (or possibly a refactor of the entire process), that's an ambush.

Double number, next highest unit of time (Score:1)

by davidwr ( 791652 )

A wise early-career mentor said time estimates should be double then use the next-highest unit of time.

1 hour becomes 2 days.

1 day becomes 2 weeks.

10 minutes becomes 20 hours.

And so on.

Sometimes you get lucky - 10 minutes becomes only 4 hours.

_
_ / \ o
/ \ | | o o o
| | | | _ o o o o
| \_| | / \ o o o
\__ | | | o o
| | | | ______ ~~~~ _____
| |__/ | / ___--\\ ~~~ __/_____\__
| ___/ / \--\\ \\ \ ___ <__ x x __\
| | / /\\ \\ )) \ ( " )
| | -------(---->>(@)--(@)-------\----------< >-----------
| | // | | //__________ / \ ____) (___ \\
| | // __|_| ( --------- ) //// ______ /////\ \\
// | ( \ ______ / <<<< <>-----<<<<< / \\
// ( ) / / \` \__ \\
//-------------------------------------------------------------\\

Every now and then, when your life gets complicated and the weasels start
closing in, the only cure is to load up on heinous chemicals and then
drive like a bastard from Hollywood to Las Vegas ... with the music at
top volume and at least a pint of ether.
-- Hunter S. Thompson, "Fear and Loathing in Las Vegas"