Semi-DCI Example

department.rb

class Department << ActiveRecord::Base
end

departments_controller.rb

class DepartmentsController
  def update_stock_value
    stock = Department.find(params[:id]).extend Roles::Stock
    stock.update
  end
end

stock.rb

module Roles
  module Stock
    def update
      # fetch value from external application and store
    end

    def value
      stock_value
    end
  end
end