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At least when I was younger I was so perplexed by the kind of co-workers that have apparently chosen the profession of working with estimates from other people
by ghotli 3y ago
At least when I was younger I was so perplexed by the kind of co-workers that have apparently chosen the profession of working with estimates from other people but continually work without a "confidence level" associated with each estimate.
("two weeks") means such a different thing in reality from ("two weeks", "confidence of 50%").
It's a tuple, it's always been a tuple, it's just downright silly to accept an estimate without the second half of the information. Like what diviniation is going on in that spreadsheet to communicate to others when it doesn't include half the meaningful information to begin with.
- robjan 3y agoIn this case why not just divide the estimate by the confidence to get the "true estimate" e.g in your example it's actually a 4 week. If you provide a tuple the confidence will eventually be conveniently dropped in some slide deck then the "2 weeks" will be socialised as the commitment.
- pph 3y agoThe estimate-confidence relation is not linear. In my experience it follows some kind of S-curve, with 0% confidence approaching impossibly short times and 100% approaching infinity (like a logistic function).
- staunton 3y agoThe logistic function is bounded, so I'm not sure what you mean...
- trashtester 3y agoTime spent is on the x-axis and confidence on the y axis. To reach 100% confidence, you have to supply an infinite estiamate.
- trashtester 3y agoI think software projects are best estimated as gamma distributions. To express that as confidence levels, you use the cumulative distribution function of the gamma, which are kind of S shaped, but stretched to the right. https://en.wikipedia.org/wiki/Gamma_distribution https://en.wikipedia.org/wiki/Gamma_distribution
- trashtester 3y agoFor instance, if you have a task that you cannot imagine taking less than 50 days, the actual time can follow the following distribution: https://www.wolframalpha.com/input?i=gamma+distribution+with+shape+7+and+scale+50 https://www.wolframalpha.com/input?i=gamma+distribution+with... And the confidence distribution would be: https://www.wolframalpha.com/input?i=cumulative+gamma+distribution+with+shape+7+and+scale+50 https://www.wolframalpha.com/input?i=cumulative+gamma+distri...
- beezlewax 3y agoIt doesn't get better with magic values like confidence levels either
- rswail 3y agoIf you feed the confidence levels into a GANTT chart, then that shows up as slack when doing the critical path analysis. But no one does that sort of thing anymore.
- ghotli 3y agoYou might imagine I disagree having written that flippant comment last night. On the contrary I've been on both sides at length over my career. While I find the tuple information somewhat useful (if I'm forced to provide semi-informed-guesses around timelines), I ultimately deep down agree with you wholeheartedly. The utility is moreso in having the conversation about why the confidence is low, which many methodologies have their own words and processes for.