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by PeterStuer 1116 days ago
The author seems to argue that estimates are off because of "unknown knowns", and can be improved by adopting an estimation framework that makes these items more explicit.

While this is certainly valid I would add that in my experience the most influential causes of major shedule disruption were the "unknown unknowns", wich are inherrent in any new creation, but which are exacerbated in software because of the extremely high and fractal dimensionality of digital assets. The smallest deviation from assuption can have an unbounded impact on the plan, often popularly refered to as a 'butterfly effect'.
2 comments
cnity 1115 days ago
Yes! I have raised several times across several teams that task estimation is a variant of the coastline paradox[0]. You'd do well to consider determining the fractal dimension of your problem domain and "sandbagging" according to the dimension.

0: https://en.wikipedia.org/wiki/Coastline_paradox

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TeMPOraL 1116 days ago
The author covers "unknown unknowns" explicity;

> It’s interesting to note: (...) the amount of work “outside” the project, aka unknown unknowns

If I understand correctly, most of those fall under the blue "Problems" category, aka. "the work outside the work" - though there may be some bleed-through to the green "Iteration" category, aka. "the work between the work", in which the author includes "debugging, refactoring, maintenance, tooling".

This is valid by my experience too; most of the schedule-breaking "unknown unknowns" fit into the "Problems" category.

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