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If you're on a sprint process, I've found it quite helpful for whoever is involved in estimation to target a "P90-confidence" estimate and round up the points..
by losteric 5y ago
If you're on a sprint process, I've found it quite helpful for whoever is involved in estimation to target a "P90-confidence" estimate and round up the points... fighting the tendency towards "average" estimation (which invariably leads to crunch). For changes that ship below estimation, use the time to vet the feature or work on other - don't immediately pick up the next sprint task.
In essence, estimate and operate with sustainability in mind.
- 9wzYQbTYsAIc 5y agoI like that idea; based on my experience, targeting with confidence intervals sounds way better than a plain average. I used to do something similar to that by making high and low estimates for each effort unit and then using the average of averages. That approach might work well for teams without a basis in operations research or statistics.
- kqr 5y agoThe strong benefit of confidence intervals is that they are empirically verifiable. If you go back and look at your past 90 % estimates and you find that not roughly 9 out of 10 were correct, you need to revise your process. Averages of averages lack this very practical, immediate interpretation.
- Buttons840 5y agoThe sum of normal distributions is a normal distribution.
- mirekrusin 5y agoYes, people don't realize that median estimate means they're expecting up front 50% chance it won't be on time, in their heads it's something weird like "almost 100% will be finished on time".