3. a) Provide a definition for the bill of materials. b) What are the principles of production control using flow? (20 marks) (20 marks) c) Warwick and Roberts Ltd. assemble light chairs for conference venues. Each chair requires an Z-shaped aluminium frame, two padded plastic panels and two aluminium handles. Three screws are used to fasten each padded plastic panel to the Z-shaped aluminium frame and two screws of the same type are used for each aluminium handle. The sales department has produced the following expected orders: Week number Predicted sales 60 2 20 3 4 40 30 The current level of stock and ordering information is as follows: Part Opening stock for week 1 Delivery time from placing order with supplier (weeks) EOQ Z-shaped 80 40 aluminium frame Padded-plastic 150 panels Aluminium 170 handles Screws 350 150 75 400 You have to answer the following questions: i) Based on the sales forecast, work out the weekly aggregate demand for each part used in the assembly process. (20 marks) ii) Generate the requirements record cards for each part for the four weeks, including the demand, opening stock, orders released and deliveries received. (20 marks) iii) Evaluate whether the current production forecast is realistic. In case any problems are found what might be done to solve them? (20 marks) (total 100 marks)