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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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Estimating/forecasting download completion time

We've all poked fun at the 'X minutes remaining' dialog which seems to be too simplistic, but how can we improve it? Effectively, the input is the set of download speeds up to the current time, and we need to use this to estimate the completion…
Phil H
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Applying HyperLogLog to a sample of the population

The HyperLogLog algorithm by Flajolet et al describes a clever way to estimate the cardinality of a set using only a tiny amount of memory. However, it does take into account all N elements of the original set in the calculation. What if we had…
Jon Smark
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Does anyone work with Function Points?

Some questions about Function Points: 1) Is it a reasonably precise way to do estimates? (I'm not unreasonable here, but just want to know compared to other estimation methods) 2) And is the effort required worth the benefit you get out of it? 3)…
torial
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Is LOC correct parameter for project estimation?

Is LOC correct parameter for project estimation? there are so many scenarios where complexity takes much more time for a single line of code, other than LOC what could be the suggested parameter for project estimation? As peoples are talking about…
Jaswant Agarwal
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How do you do very quick (and dirty) estimations for coding tasks?

So you've just been put on the spot by The Boss. You've got 15 minutes to come up with a back of the envelope estimate for the addition of some new feature. Your boss (fortunately) recognizes that you can't provide an accurate estimate in that time…
Andrew Edgecombe
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Fit distribution to given frequency values in R

I have frequency values changing with the time (x axis units), as presented on the picture below. After some normalization these values may be seen as data points of a density function for some distribution. Q: Assuming that these frequency points…
Marta Karas
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Ratio of time spent on coding versus unit testing

What is a typical estimate for coding unit tests given an estimate for coding new functionality? Is this different for estimates to maintain code?
Richard Dorman
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Computing estimated times of file copies / movements?

Inspired by this xckd cartoon I wondered exactly what is the best mechanism to provide an estimate to the user of a file copy / movement? The alt tag on xkcd reads as follows: They could say "the connection is probably lost," but it's more fun to…
Rob Burke
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How to resolve integer overflow errors in R estimation

I'm trying to estimate a model using speedglm in R. The dataset is large (~69.88 million rows and 38 columns). Multiplying the number of rows and columns results in ~2.7 billion which is outside the integer limit. I can't provide the data, but the…
James
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Software product pricing/cost estimation

I always had trouble with estimating cost/price of finished software (or programming work), so here are two questions about it. question 1: You're asked to write a piece of code for cash (all rights to the code belongs to buyer once you're done).…
SigTerm
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Why we multiply 'most likely estimate' by 4 in three point estimation?

I have used three point estimation for one of my project. Formula is Three Point Estimate = (O + 4M + L ) / 6 That means, Best Estimate + 4 x Most Likely Estimate + Worst Case Estimate divided by 6 Here divided by 6 means, average 6 and …
JEYASHRI R
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Block Bundle Adjustment Flow

I am working on bundle block adjustment for finding X,Y,Z values of image points Corrected values of camera characteristics(extrinsic parameters etc..) Corrected values of measurements In my opinion BB Adjustment process is done by following these…
AGP
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How do you measure/estimate size of XML programming effort?

To set the scene - I work in one of those industries that loves estimating and tracking pretty much everything. One of our key metrics is SLOC (source lines of code - declarative and executable statements). We use it for project size and cost…
bethlakshmi
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How Much Time Should be Allotted for Testing & Bug Fixing

Every time I have to estimate time for a project (or review someone else's estimate), time is allotted for testing/bug fixing that will be done between the alpha and production releases. I know very well that estimating so far into the future…
Yaakov Ellis
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How do you explain to a sales person that programming is really difficult and takes time

I often work with sales and marketing types that cannot figure out how to use Excel, let alone understand the scope of their requests from a technical perspective. Of course, it would not be fair to expect them to, but that still leaves me with a…
J3r3myK
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