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Use a free SPERT Excel template.

Estimate with confidence. Easily, freely.

Read the March 1, 2017 press release announcing Statistical PERT® Beta Edition.

Do you need to quickly create a reliable, confident, cost estimate or revenue projection?  How about estimating a project’s task duration, or creating a whole project forecast?  If so, then download Statistical PERT now – it’s free!

If you can render a subjective judgment about any bell-shaped uncertainty — and you have access to Microsoft Excel® 2010 or later — you can use the Statistical Program Evaluation and Review Technique (Statistical PERT® , or just SPERT®).  Statistical PERT lets anyone create a stochastic estimate or forecast using the built-in functions of Microsoft Excel.  Statistical PERT requires only two inputs to provide an infinite number of stochastic estimates for the future.  Here’s all you do:

  1. Create a 3-point estimate for an uncertainty, like task duration or an expense
  2. Render a subjective judgment about how likely the most likely outcome really is
  3. Select any probabilistic planning estimate, or make a risk-based forecast

That’s it!

Choose a cost estimate or task duration that has a very low probability of being exceeded — or cut that estimate and assume more risk that your budget or schedule won’t be enough.  Forecast revenue and see how likely your revenue estimate really is.  Estimate entire projects and create project schedules with timelines that perfectly fit your risk tolerance.  Play what-if scenarios to see how choosing different inputs into the model will affect the resulting probabilities.

You make the final call!  Using Statistical PERT, you now have a variety of probabilistic estimates at your fingertips to make the best choice.

Statistical PERT templates and example workbooks are Excel files that use standard, built-in Excel functions to forecast the future.  There is nothing to buy, nothing to install, no macros, no advertising, no adware, and no registration required!

There are two editions of Statistical PERT:  Normal Edition and Beta Edition.

  • The Normal Edition uses Excel’s two normal distribution functions, NORM.DIST and NORM.INV
  • The Beta Edition uses Excel’s two beta distribution functions, BETA.DIST and BETA.INV
  • Both editions of Statistical PERT are very easy to use

The Normal Edition is easier for a user to customize, whereas the Beta Edition is better suited to modeling a wider range of bell-shaped uncertainties, including uncertainties that are moderately-to-heavily skewed.  Both editions are freely licensed under the GNU General Public License, and both editions are ad-free and macro-free.  Download Statistical PERT example workbooks or templates now, and try using both editions of Statistical PERT!

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Statistical PERT®, SPERT®, Estimation Made Easy™, Soothsayer™ - © 2017, © 2015-2017 by William W. Davis, MSPM, PMP. All rights reserved.