Turn those off-the-cuff estimates into something more concrete your manager can be happy with.
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
spec
.travis.yml
README.md
index.js
package.json

README.md

pertestimate

Give more accurate estimates using the PERT technique

npm XO code style Build Status codecov

The PERT technique of task estimation is a trivariate estimate taking into account the best and worst possible scenarios to give a weighted average. It is also possible to calculate the standard deviation, which represents the level of confidence in the estimate.

Install

npm install --save pertestimate

Usage

pertestimate(guesstimates [, callback(results)]);

The first argument is an object with your best 'guesstimates'.

{
    best: 3,   // [Number]: The best possible outcome you can imagine, given nothing goes wrong.
    guess: 10,  // [Number]: Your initial estimate, given based on your experience.
    worst: 20   // [Number]: The worst possible outcome, given everything goes wrong.
}

The second argument is an optional callback function which receives an object containing the calculated estimate and standard deviation.

Examples

const pertestimate = require('pertestimate');

const guesstimates = {
    best: 3,
    guess: 10,
    worst: 20
}

pertestimate(guesstimates);
// --> {estimate: 10.5, deviation: -2.8333333333333335}

pertestimate(guesstimates, res => `Around ${res.estimate}, with a standard deviation of ${res.deviation}. So, most likely somewhere between ${Math.ceil(res.estimate + res.deviation)} and ${Math.ceil(res.estimate - res.deviation)}.`);
// --> "Around 10.5, with a standard deviation of -2.8333333333333335. So, most likely somewhere between 8 and 14."