Simon Willison’s Weblog

Why is software effort estimation still based on thumb rules and gut feels? How come no one has come up with an accurate estimation model?

13th October 2010

My answer to Why is software effort estimation still based on thumb rules and gut feels? How come no one has come up with an accurate estimation model? on Quora

For a truly accurate estimation, you need to have built the software before. If you’ve built it before, why are you building it again?

Posted 13th October 2010 at 5:06 pm · Follow me on Mastodon, Bluesky, Twitter or subscribe to my newsletter

More recent articles

Highlights from my appearance on the Data Renegades podcast with CL Kao and Dori Wilson - 26th November 2025
Claude Opus 4.5, and why evaluating new LLMs is increasingly difficult - 24th November 2025
sqlite-utils 4.0a1 has several (minor) backwards incompatible changes - 24th November 2025

This is Why is software effort estimation still based on thumb rules and gut feels? How come no one has come up with an accurate estimation model? by Simon Willison, posted on 13th October 2010.

software-engineering 60 web-development 169 quora 1005 product-management 9

Next: Who is the most recognizable person in the world (real or fictional; alive or dead)?

Previous: Simon Willison: How do you configure the Apache server you describe in What are the advantages of running Apache behind nginx as opposed to just Apache by itself?

Monthly briefing

Sponsor me for $10/month and get a curated email digest of the month's most important LLM developments.

Pay me to send you less!

Sponsor & subscribe