Earned Value Calculator

Ruby Gem Version Ruby Style Guide CircleCI

evm

Calculates the earned value of a project to indicate a diagnosis result.

What is Earned value management ?

Earned value management (EVM) is a project management technique for measuring project performance and progress in an objective manner by Earned value management - Wikipedia.

Installation

Add this line to your application's Gemfile:

gem 'earned_value_calculator'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install earned_value_calculator

Usage

Given a project parameters, the calculator output the earned value of the project. Start date, end date, current date, budget, progress rate and actual total cost are required.

project = EarnedValueCalculator.call(Date.today - 3,
                                     Date.today + 3,
                                     Date.today,
                                     100,
                                     10,
                                     10)
project.planned_value
#=> 50

Features

Calculates these metrics of a project:

  • earned_value
  • planned_value
  • schedule_variance
  • actual_cost_variance
  • cost_performance_index
  • schedule_performance_index

earned_value (EV)

EV is calculated by multiplying %complete of each task (completed or in progress) by its planned value. It is based on the formula:

planned_value (PV)

schedule_variance (SV)

It is based on the formula:

SV = EV - PV

actual_cost_variance (CV)

It is based on the formula:

CV = EV - AC

cost_performance_index (CPI)

It is based on the formula:

CPI = EV ÷ AC

schedule_performance_index (SPI)

It is based on the formula:

SPI = EV ÷ PV

estimate_at_completion (EAC)

It is based on the formula:

EAC = AC + (BAC - EV) ÷ CPI = AC + ETC

estimate_to_completion (ETC)

It is based on the formula:

ETC = (BAC - EV) ÷ CPI = EAC - AC

variance_at_completion (VAC)

It is based on the formula:

VAC = BAC - EAC

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Test

rspec spec

Contributing

Bug reports and pull requests are welcome on BitBucket at https://github.com/routeflags/earned_value_calculator. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the EarnedValueCalculator project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.

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Аcknowledgments