I need to re-evaluate time for remaining tasks based on the actual time and estimated time of completed tasks.

For example if a small project had 4 tasks and each task was estimated at 2 days. Lets say 2 tasks were completed at 4 days each, the reminding tasks should be projected to be completed in 4 days, therefore re scaling all the remaining tasks and getting a new project time line, with each reminding task being projected to 4 days as well.

Anyone know of such a auto estimation and projection algorithms ?

  • 1
    But a question about the underlying methodology algorithms would be on topic and worthy of upvote
    – MCW
    Apr 11, 2015 at 14:06
  • Take a look at Earned Value Management. Apr 19, 2015 at 14:11

2 Answers 2


Earned Value Management (EVM) techniques specify a number of formulas to calculate a project's Estimate At Complete (EAC) based on the estimates and actuals for completed tasks. Essentially they use past performance as a predictor of future performance.

Section 2.2 of the Defense Contract Management Agency (DMCA) EVMS Program Analysis Pamphlet documents these approaches:


These equations are known as IEAC (I = independent) because the typical EAC number is provided by program management as an estimate of future work based on the original budget and NOT corrected for past performance.

The link has a good description of the formulas and how all the inputs are calculated. None of it is too complicated, but it’s the subject of a whole course and definitely beyond the scope of a single answer.


Both Earned Value and Earned Schedule methods will provide the formulas that will compute different estimate at completion values based on what you input as actuals. There are an infinite number of calculations you can make to give you a nice distribution of EAC values. Those calculations coupled with an expert re-estimation of remaining work should give you a credible result.

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