An MRP Explosion Brunswick Motors Recently, Phil Harris, the Production Control Manager at Brunswick, read an article on Time-Phased Requirements Planning. He was curious about how this technique might work in scheduling Brunswicks engine assembly operations, and decided to prepare an example to illustrate the use to Time-Phased Requirements Planning. Phils first step was to prepare a master schedule for one of the engine types produced by Brunswick - the Model 1000 engine. This schedule indicates the number of units of the Model 1000 engine to be assembled each week during the past twelve weeks, and is shown below. Engine Assembly Master Schedule Week 1 2 3 4 5 6 7 8 9 10 11 12 Demand 13 6 8 10 18 24 14 8 2 15 Next, Phil decided to simplify his requirements planning example by considering only two of the many components that are needed to complete the assembly of the Model 1000 engine. These two components, the Gear Box and the Input Shaft, are shown in the Product Structure Diagram shown here. Phil noted that the Gear Box is assembled by the Sub-Assembly Department, and is subsequently sent to the main engine assembly line. Therefore, the engine assembly master schedule determines the weekly gross requirements for the Gear Box. The Input Shaft is one of several component parts manufactured by Brunswick that are needed to produce a Gear Box sub-assembly. Thus, levels 0, 1, and 2 are included in the Product Structure Diagram to indicate the three manufacturing stages that are involved in producing an engine: the Engine Assembly Department, the Sub-Assembly Department, and the Machine Shop. The manufacturing lead times required to produce the Gear Box and Input Shaft components are also indicated in the Product Structure Diagram. Note that two weeks are required to produce a batch of Gear Boxes, and that all of the Gear Boxes must be delivered to the assembly line parts stockroom before Monday morning of the week in which they are to be used. Likewise, it takes three weeks to produce a lot of Input Shafts, and all of the shafts that are needed for the production of Gear Boxes in a given week must be delivered to the Sub-Assembly Department stockroom before Monday morning of the week. In preparing the MRP example Phil made the following assumptions: Seventeen gear boxes are on hand at the beginning of Week 1, and six gear boxes are currently on order to be delivered at the start of Week 2. Forty-six input shafts are on hand at the start of Week 1, and 18 are scheduled for delivery at the beginning of Week 2. Initially, assume that Phil wants to minimize his inventory requirements. Assume that each order will be only for what is required for a single period. Gear Box Requirements Input Shaft Requirements Phil would like to consider the costs that his accountants are currently using for inventory carrying and setup for the gearbox and input shafts. These costs are as follows: Part Cost Gear Box Setup = $120/order Inventory Carrying Cost = $2/unit/week Input Shaft Setup = $60/order Inventory Carrying Cost = $1/unit/week Question 1. Complete the MRP table for Gear Box using the lot-for-lot (L4L) lot sizing technique. Use the numbers in the engine assembly master schedule, directly, for the weekly Gear Box gross requirements. What are the total costs of schedule for Gear Box based on the L4L technique? Having the completed MRP table for Gear Box, based on the L4L lot sizing technique, answer the following questions: Question 2. Complete the MRP table using the lot-for-lot (L4L) lot sizing technique for Input Shaft. What are the total costs of schedule for Input Shaft based on the L4L technique? Question 3. Complete the MRP table using the EOQ lot sizing technique for Input Shaft . Assume the total annual demand for Input Shaft is D= 2496 units. what are the total costs of schedule for Input Shaft based on the EOQ technique? Question 4.Complete the MRP table using the least total cost (LTC) lot sizing technique to determine the first planned order quantity for Input Shaft. The second order quantity must meet the requirements of Input Shaft to the end of week 12. What are the total costs of schedule for Input Shaft? Question 5. Complete the MRP table , using the least unit cost (LUC) lot sizing technique to determine the first planned order quantity for Input Shaft. The second order quantity must meet the requirements of Input Shaft to the end of week 12. What are the total costs of schedule for Input Shaft?