What do you need in an emergency? If it's a medical emergency Wheeled Coach has it covered. Based in Winter Park Florida Wheeled Coach is the nation's largest manufacturer of custom built ambulances that handle everything from routine hospital transports to full scale trauma and disaster services. You may think that ambulances are pretty much all the same but in fact each Wheeled Coach ambulance is built from the ground up using 12 major platforms to meet the specific and unique requirements of every buyer. The custom nature of Wheeled Coach's business means that there are thousands of different configurations that plant personnel must be able to assemble efficiently. Because the vehicles are all distinct Wheeled Coach uses a job costing system to accumulate costs separately for each ambulance manufactured. No vehicle begins production until all required materials are in inventory. Materials include Ford Truck chassis, aluminum for framing, wood products for cabinets and wiring for electrical systems. Wheeled Coach has close to 20,000 items called stock keeping units in its inventory some of which arrive just in time for production. The goal of the company's 6 assembly lines is to roll a finished vehicle off the line each day. Close to 350 employees work four 10 hour a day shifts per week to achieve this goal. The main assembly lines are fed daily from subsidiary job shops near the main production floor. Some of the job shops include 1-Carpentry for interior benches and cabinets 2-Upholstery for seating 3-Metal fabrication for the ambulance's shell 4-Paint shop for truck chassis prep, painting, and exterior detailing 5-Electrical for wiring 6-Plexiglass for interior cabinet window fabrication All work is done to meet individual job specifications so no finished goods inventory is made to stock. A detailed bill of materials is used to request and issue direct materials to the job shops and the main assembly floor. To keep assembly moving each day Wheeled Coach must balance its assembly line work areas called cells so that just enough workers and labor stands idle, too few workers and the work tasks do not get finished by shift's end backing up the line and triggering overtime. All work completed in each station moves into the next cell at day's end so that the workers are not kept waiting the following day.

question

Describe what types of source documents you would expect Wheeled Coach to use in their job costing system.