[Chris2048]

> for those estimates to be useful in tracking your progress you have to do it in advance

In advance of what? The only constraint on a useful estimate is that is comes before the task is finished - it needn't be considered as credible at the earliest possible time.

Also, your response doesn't really address my post..

[cechner]

(I went to bed so didn't take long to reply before)

I am clearly not expressing myself well. I am talking about a situation where some stakeholders are expecting a complete picture of roughly how large the project is and would like to be able to track how far your team is through this project on a regular basis.

I am putting scrum forward as a methodology for, in as short a time as possible, measuring the size of that project in a meaningful way by merely breaking it up into as small pieces as possible and attaching numbers to those pieces, intended to measure the size of each piece relative to the other pieces, and then over time discovering how long it takes to complete a piece of a given size.

> Assume each person giving different estimates for their own work, but not up front - ongoing as code is written.

The situation I outlined above (the time when scrum helps out) requires you have a stab at estimating all the constituent parts of the project at the beginning of the project.

> an estimate is an estimate, not a commitment. Committing to an estimate makes it a commitment, not an estimate.

True, but the point of estimating in scrum is to assign relative sizes to the pieces of work, not a number of hours, so this isnt a commitment to finish at a specific time but just to say 'I think this is one of the larger pieces of work in this project.' The person I was replying to sounds like they are on a bad team/project where people use their estimates to blame/finger point, and they are ascribing this to scrum as if the team wouldnt be doing this otherwise.

And in case you suggest that estimating without ascribing a time value is not meaningful, it is used to track how far you are through the project, and over time you refine what the finishing date will be given the emerging velocity.

> I might expect a dice roll to be 3.5, I'm not committing to the next roll being 3.5 - analysis should inform policy, in this case expectations informing stated commitments, but the two are not the same.

The analysis comes in discovering the velocity. The expectations evolve over time. But knowing your velocity is of limited use if you dont have an estimate of the overall size of the project.

> The difference is choosing to commit to an estimate you have high confidence in

This is the method for getting confidence in your estimate. You have an overall number of 'points' in the project and you learn how many points you can tackle on average every X weeks.

[crdoconnor]

>The person I was replying to sounds like they are on a bad team/project where people use their estimates to blame/finger point, and they are ascribing this to scrum as if the team wouldnt be doing this otherwise.

Every time you try and infer what I'm "really" saying or what "really" happened to me you get it completely wrong. Next time you do that just assume that you're wrong, it'll save us both time.

The blame/finger pointing on my projects wasn't really external (although in a different environment it certainly could have been). Developers themselves felt bad about missing their 'commitments'. The pressure/blame was largely self-inflicted.

Despite feeling bad the predictions were still consistently optimistic and still consistently wrong due to the environment the predictions were made in. It was a bug in the scrum process that led this to happen, but the team and management (and you, apparently) would rather assign blame to anything else other than a bug in their methodology.

>The analysis comes in discovering the velocity.

Velocity isn't a useful metric.

>This is the method for getting confidence in your estimate.

Except it doesn't work. It didn't work for us and it probably doesn't work for anybody else.

Confidence in estimates means treating risk and uncertainty as if it is real rather than sweeping it under the carpet, like it is in scrum.

Confidence means a prediction process that doesn't make developers feel guilty about being wrong, like it does with scrum 'commitments'.

Confidence a prediction process that doesn't intentionally subject developers to groupthink and peer pressure by immediately putting them on the spot like scrum planning pt 2 does.

Confidence means that your estimation process itself should be mutable. Under scrum it is fixed and not subject to review (if you change it you're doing "Scrum-but" and that's a sin, according to scrum trainers).

Most of all, confidence means that you should be able to inject technical debt cleanup stories into the sprint that derisk future changes. Scrum says that's only allowed if the PO says it's allowed. The PO is not responsible for missed commitments though, so it's not their problem.