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Questions tagged [estimation]

Questions related to tips and techniques about software project estimations: development time, effort, team size, software size, execution time, run time resource usage. Please ask on https://softwareengineering.stackexchange.com/help/on-topic if your question is not directly related to code.

Fred Brooks said:

It is very difficult to make a vigorous, plausible and job-risking defense of an estimate that is derived by no quantitative method, supported by little data, and certified chiefly by the hunches of the managers

On a day-to-day business context, the word estimate is often used when asking for a commitment, and this is incorrect. An estimate is not a target, not a commitment. An estimate is an assessment, based on prior experience, judgement and possibly on incomplete information about the time or resources needed to build a software project. An estimate can also be requested for the size or configuration or system resources needed to execute a software product.

Estimates always have a degree of error, so this should always be kept in mind when using an estimate to make a decision. More precision is achieved for an estimate spending more time or money - an estimate may be quick, precise and inexpensive: pick two of the three attributes.

Books about software estimation:

  • Software Estimation. Demystifying the Black Art. Steve McConnell. 2006 Microsoft Press, Redmond, WA.

  • Software Engineering Economics. Barry W. Boehm. 1981 Prentice-Hall Inc. Englewood cliffs, NJ.

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How can I estimate gaussian (mixture) density from a set of weighted samples?

Assume I have a set of weighted samples, where each samples has a corresponding weight between 0 and 1. I'd like to estimate the parameters of a gaussian mixture distribution that is biased towards the samples with higher weight. In the usual…
Christian
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Probability theory and project planning

I'm managing a project that has to be estimated, according to rough requirements and specifications. Because of that, the estimations on the specific features and tasks are set of discrete values, instead of just one discrete value (for example,…
Dimitar Dimitrov
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How to use linear interpolation estimate current position between two Geo Coordinates?

I have the following available: last reported lat,lon w/timestamp target lat,lon estimated time to target heading How can I interpolate an estimated position over time? I know that's enough to calculate the required average velocity for the…
Mark Renouf
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How to work unestimatable tasks into a scrum sprint?

I am the scrum master for a small team of 4 developers. The project we are working on has a lot of tasks that we have never done before and cannot easily estimate in a sprint planning meeting. What is the best way for me to run a sprint with this…
Dave K
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How to predict system resource need?

Is there any software or way to predict system resource need by taking several inputs such as MySQL query read/write ratio, queries executed in a second, properties of tables and databases, maybe some more inputs related with PHP configurations etc.…
user1055645
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What are the limitations of Gitlab Community Edition (Gitlab CE)?

I read this comparison https://about.gitlab.com/pricing/self-managed/feature-comparison/ on Gitlab, lot of things are still unclear. I would like to ask about the limitation at some points: limitation for general element type (number of people,…
Thach Lockevn
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R: trouble with mle() error: non-finite finite-difference value [2]

I have a simple x, y data.frame. mydata <- data.frame(days = 1:96, risk = c(5e-09, 5e-09, 5e-09, 1e-08, 4e-08, 6e-08, 9e-08, 1.5e-07, 4.2e-07, 7.2e-07, 1.02e-06, 1.32e-06, 1.66e-06, 2.19e-06, 2.76e-06,…
Adrian
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How to estimate times when working on a new technology?

I have been working on Flex for last couple of months and as this was the first time I had to actually do Flex I ended up underestimating the project tasks which resulted in a delay. So how does one estimate the project timings when working on a new…
andHapp
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Using Scrum in fix-length/fix-priced projects?

I'm a Scrum newbie and looking to implement Scrum in my company. Obtaining buy-in is not a problem, it is my company and the developers are more than happy to work like this. The problem is that 75% of our revenue is derived from fixed length/fixed…
Jason
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How to change to use Story Points for estimations in Scrum

Having used "days" as the unit for estimation of tasks in Scrum I find it hard to change to using Story Points. I believe story points should be used as they are more comparable to each other - being less dependent on the qualifications of whoever…
stiank81
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tracking square root of moving value

I have a control loop running at high frequency and need to compute a square root each cycle. Typical square root functions work fine but take excessive time. Since the value I'm taking the square root of doesn't change too much on each cycle, I…
phkahler
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Estimating Time on Tasks

We have just started doing scrum at my company. We are spending a bit of time estimating Effort using planning poker and then when the detailed tasks are worked out a time estimate is put on each task. The problem we have is that the time estimates…
Greg
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Should project manager ask how much time will it take to implement some functionality?

Our project manager usually consult developers how many hours they need to implement some functionality asked by client. Is this consistent with the principles of management? Do you or your project managers do the same?
Alexander Prokofyev
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Numerical Method for SARIMAX Model using R

My friend is currently working on his assignment about estimation of parameter of a time series model, SARIMAX (Seasonal ARIMA Exogenous), with Maximum Likelihood Estimation (MLE) method. The data used by him is about the monthly rainfall from 2000…
crhburn
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What functionality should always be third-party?

What prompts my question is this post from Jeff Atwood, and this post from Dare Obasanjo. It seems to me that there might be at least a few areas where third-party functionality is a better idea than custom code. For example, should logging always…
Scott Lawrence
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