534 Chapter 13 Material Requirements Planning and Enterprise Resource Planning The manager heard about MRP, and wants to use it. DMD makes two types of bikes: Arrow and Dart. Suppose that 15 Arrows and 10 Darts are needed at the beginning of each week for weeks 4 through 8. The product structure trees for the two bikes follow. Arrow Dart e e X M w K2) F | R F w2 aQ *LT = 3 weeks for orders of 36 or more units. He has collected the following information on lead times, inventory on hand, and lot-sizing methods Scheduled receipts are: (established by suppliers and/or DMD): Week 1: 20 A 5. 18 Ws Week 2: 20 Darts, 15 Fs Item m On Hand Method Develop the material requirements plan for all the items. Mini-Case Im MINI-CASE Zurn Zurn makes various plumbing products such as fixtures, faucets, drainage equipment, and valves (under the Wilkins brand name). The plant manager is concerned with excessive amounts of inventory of parts in the plant. The materials manager has been tasked to identify if these inventories can be reduced. Zurn uses an accounting software, which also has an MRP module. The materials manager has chosen a popular and reliable pressure vacuum breaker valve (backflow preventer), Model 720A, to study. Model 720A consists of various parts, most made in the plant but some bought from suppliers, both domestic and Asian. The BOM and assembly chart for 7204 are displayed below. Note that there is a repair kit for Model 720A (in the bottom of the BOM). This is used by some contractors to repair a faulty installed Model 720A and replaces only the internal parts of the *pressure valve. The weekly forecast demands for 720A and repair kit for the next quarter (13 weeks) are fairly constant: Item 7204 Repair kit Courtesy of Zurn Industries, LLC., https/fwww zurn.com/products/water d =T [unrls} 1154 135 -safety/backflow-prevention/720aM1-720a MODEL 720A ZURN Pressure Vacuum Breakers - 1/2" to 1" Repair Kit Components 1/2" - 1" Item # Item Description 2 RX1-720AP RK1-720A RK1-720AB 1 Screw, Canopy 2 Canopy (3 Bonne . . Washer. Bonnet 4 0-Ring, Bonnet 6 Load Nut and Guide 7 Load Washer . . . Disc, Upper LD 00 Poppet 000 - 106 10 Spring 11 Screw, Spider 12 Disc, Lower Guide Spider Nut, Hex Whole Goods (Available for individual sale) Item # Item Description 1/2" 3/4 15 Test Cock 18-860XL 16 Ball Valve, Tapped 12-850T 34-850T 1-8501 10 Item No. Repair Kit Description /2" - 1" 11 RK1-720A Complete Repair Kit, 1/2 - 1" 720A RK1-720AB Bonnet Repair Kit, 1/2 - 1" 720A 12 RK1-720AP Poppet Repair Kit, 1/2 - 1" 720A 13 14To save time, the materials manager has decided to look atthe Questions requirements plans for only the following components: body, plastic washer, and ball valves. In addition to Model 720A and repair kit, some of these components are used in other valves as well. The weekly forecast demands for these components for the next quarter (13 weeks) are fairly constant: tem Body Plastic washer Ball valve * only weeks 9-13 Some more information about these five items is as follows: Lead Time Safety Currently Repair kit 1 360 LAl 434 Plastic washer 5 9,000 55,000 16.680 1. What are the requirements for these five items for the next 13 weeks? 2. Is Zurn carrying too much inventory? (Hint: Look at on-hand, safety stocks, and lot sizes.)