Transcript Bill of materials (BOM) - Faculty of Computer Science and

Bill of Materials
Contents






Definition of a bill of materials
How a bill of materials is used
Types of bill of materials
Bill of materials information
Benefits of a bill of materials
Examples of bill of materials
2
Definition

Bill of materials (BOM): a listing of all of the raw
materials, parts, subassemblies, and assemblies
needed to produce one unit of a product.


Each finished product has its own bill of materials.
Product structure tree: Visual depiction of the
requirements in a bill of materials, where all
components are listed by levels.
3
Bozarth, Cecil C. and Handfield, Robert B. Introduction to Operations and Supply Chain Management
. Pearson Education, Inc., Upper Saddle River, New Jersey, 2006. p.461.
Definition Explained


Basically, a bill of material (BOM) is a
complete list of the components making
up an object or assembly.
It is also part of material requirements
planning (MRP) input.
4
Processes that utilize a BOM




Production
Materials planning
Product costing
Plant maintenance
5
Types of BOMs

Static (fixed) bill



A bill of material for a part that is normally made
from the same components, labor and raw
materials.
Used for standard assemblies, components, and
engineer-to-order customer orders.
Example:

A bill of materials for a standard chair
6
Types of BOMs

Dynamic (parametric) bill


A bill of material for a product or part for
which size, color, laminate, and other
options can be selected.
Example:

A bill of materials for a Dell computer
7
Structure of a BOM
8
What information is on a
BOM?
1.
2.
3.
4.
5.
Quantity
Item ID#
Description of Item
Cost of Item
Total Project Cost
9
Quantity

Tells user how many of each part is
needed for each project

Example:

A chair needs 1 seat, 4 legs, 1 back, and 5
nails.
10
Item ID #


Tells us which part to order
Can be any of the following:


Catalog number, UPC, or any other identification
number.
Example:

The chair needs a 2PC seat, 5DR legs, 6TU8
back, and 1 inch nails.
11
Description of Item

Provides a check that the correct item
is being ordered.
12
Cost of Item

Cost is included to show how much each
part is per item and the total cost of all like
parts.

Example:

The cost of a leg is $5 per leg. Then the total
price of the legs ordered would be $20 because
there are 4 legs.
13
Total Project Cost

Shows the total cost of all items and is also
the total cost of the direct materials used in
the project.

Example:


Seat-$10, Back-$5, Leg-$5 per leg, Nail-$.5 per
nail
Total Cost of a chair = 10 + 5 + 5*4 + .5*5 =
$37.50
14
BOM Example
Quantity
Cost
ID#
Description
Unit Price
Total
1
4
1
5
6TU8
5DR
2PC
1”
Back
Legs
Seat
Nails
$5/Unit
$5/Unit
$10/Unit
$0.50/Unit
$ 5.00
20.00
10.00
2.50
Total Project Cost
$37.50
15
Assembly Diagram & Product
Structure Tree
16
Example
17
Example 1 (Cont.)

Using the information above to do the
follows:
a) Determine the quantities of B, C, D, E,
and F needed to assemble one X.
18
a).
X X1 : 1
Solution to Example
B : 2 1  2 B(2)
D : 3  2  6 D(3)
E : 4  6  24
E(4)
C C : 1 1  1
E

E : 1 2  2
E(2)
F(2)
E : 2 1  2 F : 2 1  2
Thus, one X will require
•
B: 2
C: 1
•
D:6
F: 2
•
E: 28 (Note that E occurs in three places, with
2+2+24)
19
Example 1 (Cont.)

Using the information above to do the follows:
a) Determine the quantities of B, C, D, E, and F needed to
assemble one X.
b) Determine the quantities of B, C, D, E, and F needed to
assemble ten X's, if you have the following in inventory:
Component On hand
B
4
C
10
D
8
E
60
20
b).
Component On hand
B
4
C
10
D
8
E
60
X X1: 10
Solution to Example
(Cont.)
B : 2  10  20
C : 110  10
 4 B(2)
16
 10 C
0
D : 3 16  48
 8 D(3)
40
E(4)
E : 4  40  160
 60
100
E

E : 116  16
E :0
E(2)
F :0
F(2)
Thus, given the amounts of on-hand
inventory, 10 Xs will require
•
B: 16
C: 0
•
D: 40
F: 0
•
E: 116 (=16+100)
21