customer_repair_order.rb

class CustomerRepairOrder < RepairOrder
end

order.rb

class Order < ActiveRecord::Base
end

recall_repair_order.rb

class RecallRepairOrder < RepairOrder
  def recall_date
    #logic
  end
end

repair_order.rb

class RepairOrder
  def recall_date
    ""
  end
end

repair_order_factory.rb

class RepairOrderFactory
  def self.build(data)
    case data.type
    when "warranty"
      WarrantyRepairOrder
    when "recall"
      RecallRepairOrder
    else
      CustomerRepairOrder
    end.new(data)
  end
end

repair_orders_controller.rb

class RepairOrdersController < ApplicationController
  def show
    order = Order.find_by(id: params[:id])
    @repair_order = RepairOrderFactory.build(order)
  end
end