application_helper.rb

class WorkUnit
  scope :on_estimated_ticket, lambda{ include(:ticket).where("tickets.estimated_hours IS NOT NULL AND tickets.estimated_hours > 0") }
end

  def project_completion_metric(project)
    work_unit_hours_array = Array.new # Empty array to work with

    # Take the summation of estimated_hours on a ticket from the project
    estimated_hours       = Ticket.for_project(project).sum(:estimated_hours)
    
    # Push the work unit hours in if the ticket on the project has estimated hours
    work_unit_hours = WorkUnit.for_project(project).on_estimated_ticket.sum(:hours)
    
    # Calculatre the projects completion as a percent
    percent = (((work_unit_hours / estimated_hours)).to_f * 100.00).round(2) rescue 0
    [percent, 100].min # Make sure you don't go over 100 percent and confuse the graphs
  end