COCOMO 81 Time-Delivery calculation module (based on JUAS software metrics report)

workperiod.ps1

<#
.SYNOPSIS
Calculate an optimul project work period from a man months.

.INPUTS
None.

.OUTPUTS
None.

.EXAMPLE
C:\PS> powershell -ExecutionPolicy RemoteSigned
Windows PowerShell
Copyright (C) Microsoft Corporation. All rights reserved.

PS C:\PS> . .\workperiod.ps1
PS C:\PS> $wp = [WorkPeriod]::new()
PS C:\PS> $wp.Period(12)
5.72357121276666
PS C:\PS> $wp.MinPeriod(12)
4.29267840957499
PS C:\PS> $wp.HeadCount(12)
2.09659311536712
PS C:\PS> $wp.MaxHeadCount(12)
2.79545748715616
PS C:\PS> $wp = [WorkPeriod]::new([Factor]::JUAS_2016)
PS C:\PS> 12, 24, 36 | %{ $wp.Period($_) }
5.95251406127733
7.49969776559852
8.58501084712603
#>

Set-StrictMode -Version Latest

enum Factor {
    Boehm_1981
    JUAS_2007
    JUAS_2016
}

class WorkPeriod {
    hidden [double] $_WorkPeriodFactor
    hidden [double] $_MinPeriodRatio

    hidden [void] _Init([Factor] $factor) {
        switch ($factor) {
            Boehm_1981 {
                $this._WorkPeriodFactor = 2.5
                $this._MinPeriodRatio = 0.75
            }
            JUAS_2007 {
                $this._WorkPeriodFactor = 2.4
                $this._MinPeriodRatio = 0.70
            }
            JUAS_2016 {
                $this._WorkPeriodFactor = 2.6
                $this._MinPeriodRatio = 0.70
            }
            default {
                throw "unknown argument: $factor"
            }
        }
    }

    hidden [double] _CubeRoot([double] $n) {
        return [Math]::Pow($n, 1.0 / 3.0)
    }

    WorkPeriod() {
        $this._Init([Factor]::Boehm_1981)
    }

    WorkPeriod([Factor] $factor) {
        $this._Init($factor)
    }

    [double] Period([double] $ManMonth) {
        if ($ManMonth -lt 1) {
            throw 'argument must be greater than or equal to 1'
        }
        return $this._WorkPeriodFactor * $this._CubeRoot($ManMonth)
    }

    [double] MinPeriod([double] $ManMonth) {
        if ($ManMonth -lt 1) {
            throw 'argument must be greater than or equal to 1'
        }
        return $this.Period($ManMonth) * $this._MinPeriodRatio
    }

    [double] HeadCount([double] $ManMonth) {
        if ($ManMonth -lt 1) {
            throw 'argument must be greater than or equal to 1'
        }
        return $ManMonth / $this.Period($ManMonth)
    }

    [double] MaxHeadCount([double] $ManMonth) {
        if ($ManMonth -lt 1) {
            throw 'argument must be greater than or equal to 1'
        }
        return $ManMonth / $this.MinPeriod($ManMonth)
    }
}

workperiod.rb

# frozen_string_literal: true
# encoding: utf-8
# -*- coding: utf-8-unix -*-
# vim:fileencoding=utf-8:ff=unix
#
# workperiod.rb - Calculate an optimul project work period from a man months.

class WorkPeriod
  module Constants
    # B. W. Boehm, Softwore Engineering Economics
    FACTOR_BOEHM_1981 = 0
    # JUAS software metrics report 2007
    FACTOR_JUAS_2007 = 1
    # JUAS software metrics report 2016
    FACTOR_JUAS_2016 = 2
  end
  include Constants

  def initialize(factor=FACTOR_BOEHM_1981)
    case factor
    when FACTOR_BOEHM_1981
      @WORK_PERIOD_FACTOR = 2.5
      @MIN_PERIOD_RATIO = 0.75
    when FACTOR_JUAS_2007
      @WORK_PERIOD_FACTOR = 2.4
      @MIN_PERIOD_RATIO = 0.70
    when FACTOR_JUAS_2016
      @WORK_PERIOD_FACTOR = 2.6
      @MIN_PERIOD_RATIO = 0.70
    else
      raise ArgumentError, "unknown argument: #{factor}"
    end
  end

  # The optimul work period for a man_month size project.
  def period(man_month)
    raise ArgumentError, 'argument must be greater than or equal to 1' unless man_month >= 1
    @WORK_PERIOD_FACTOR * cbrt(man_month)
  end

  # The minimum work period for a man_month size project.
  def min_period(man_month)
    raise ArgumentError, 'argument must be greater than or equal to 1' unless man_month >= 1
    period(man_month) * @MIN_PERIOD_RATIO
  end

  # The optimul headcount for a man_month size project.
  def headcount(man_month)
    raise ArgumentError, 'argument must be greater than or equal to 1' unless man_month >= 1
    man_month / period(man_month)
  end

  # The maximum headcount for a man_month size project.
  def max_headcount(man_month)
    raise ArgumentError, 'argument must be greater than or equal to 1' unless man_month >= 1
    man_month / min_period(man_month)
  end

  private

  # Cube root.
  def cbrt(n)
    n ** (1.0 / 3.0)
  end
end