Need done ASAP!!
A n a l y t i c s E x e r c i s e : A n M R P E x p l o s i o n —
B r u n s w i c k M o t o r s
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 Brunswick’s engine assembly operations
and decided to prepare an example to illustrate the
use of time-phased requirements planning.
Phil’s 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 last 12 weeks and is shown below. 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 below. Phil noted that the
gear box is assembled by the Subassembly Department and
subsequently is sent to the main engine assembly line. The
input shaft is one of several component parts manufactured
by Brunswick that are needed to produce a gear box subassembly.
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 Subassembly 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 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 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 that week.
In preparing the MRP example Phil planned to use the
worksheets shown on the next page and to make the following
assumptions:
1. Seventeen gear boxes are on hand at the beginning of
Week 1, and five gear boxes are currently on order to
be delivered at the start of Week 2.
2. Forty input shafts are on hand at the start of Week 1,
and 22 are scheduled for delivery at the beginning of
Week 2.
Q u e s t i o n s
1. 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. Using the
following forms, calculate the net requirements and
planned order releases for the gear boxes and input
shafts. Assume that lot sizing is done using lot-for-lot
(L4L).
2. Phil would like to consider the costs that his accountants
are currently using for inventory carrying and
setup for the gear boxes and input shafts. These costs
are as follows:
Part Cost
Gear Box Setup = $90/order
Inventory carrying cost = $2/unit/week
Input Shaft Setup = $45/order
Inventory carrying cost = $1/unit/week
Given the cost structure, evaluate the cost of the
schedule from question 1. Assume inventory is valued
at the end of each week.
3 Find a better schedule by reducing the number of
orders and carrying some inventory. What are the
savings with this new schedule?