Estimate

In preparing for [projects] I have always found that [estimates] are useless, but [estimating] is indispensable.

—General Dwight D. Eisenhower

It’s better to be roughly right than precisely wrong

—Maynard Keynes

We keep on estimating and planning according to those estimates, expecting to meet deadlines and firing the wise fools that question the practice, and report the actual numbers that are not accepted by management. However…

Insanity: Doing the same thing over and over and expecting different results.

—Albert Einstein

Watch out for:

Estimates become targets.

—Esther Derby

Use yesterday’s weather, which implies “results from the past give guarantees for the future”.

Collect metrics about the real system, like average lead time distribution, cumulative flow diagram, average throughput, and predictability.

Thou shalt not treat estimates as commitments.

Setting deadlines and promises based on estimates is dysfunctional.

• → metrics drive behavior
• → relative estimation
• http://www.djaa.com/noestimates-beef-and-agiles-trojan-horse
• #noestimates
• http://en.wikipedia.org/wiki/Probabilistic_method
• http://www.infoq.com/articles/software-development-effort-estimation
• http://softwaredevelopmenttoday.blogspot.co.nz/2012/01/story-points-considered-harmful-or-why.html
• http://www.infoq.com/resource/minibooks/emag-agile-estimation/en/pdf/Agile-Project-Estimation-and-Planning-eMag.pdf

See plastic plan.