Bills of Materials in Technical Data Management
1
e-Prelude.com
Technical Data Management
Bills of Materials
2
Bills of Materials
•
C
o
n
t
e
n
t
–
BOM types
–
Intermediate Level Creation
–
Phantom Items
–
Common BOM
–
Link Offset
–
BOM evolution
–
By-products and co-products
–
BOM Variants
–
Linking components to routing operation
3
BOM decimals
•
For each item, the number of decimals
used for the coefficient of its BOM links
should be specified
•
Examples:
–
Assembled product: 0 decimal
•
Only an integer number of components can be
mounted
–
chemical combination: 4 decimals
•
0.0253 kg for a component
4
Which components should be
recorded in the BOMs?
•
Should be recorded in the bills of materials
–
all materials and all components
–
including waste packaging
•
Should NOT be recorded in the bills of materials
–
components with erratic consumption and/or with a
very low cost
•
examples: oil, stretch films, tags
–
recyclable packaging
•
examples: containers, pallets, ...
5
BOM types
•
Engineering
BOM
–
created by the
Product engineering department
–
Used during product design phases and development
(up to prototyping)
•
Manufacturing
BOM
–
created by the
Process engineering department
–
maintained by the plants
•
Budget (or Frozen)
BOM
–
Used as budget reference
–
Created by the
Frozen Data Creation
function (
Costing
menu)
•
Select the date for link selection
•
Creates a copy of valid links
6
BOM types
An manufactured item can have several BOMs
Select the BOM type in the drop-down list
7
Engineering BOM
•
Structure depends on
Product engineering
department
working methods
•
Product Breakdown usually by functions
•
Gradual development
•
Choices technical performance - manufacturing
cost
•
Transfer to manufacturing
8
Manufacturing BOM
•
Structure depends on the manufacturing steps
of a product
•
Created by the
Process engineering
department
when it enters the routings
•
It must be verified that, at the lowest level, all
the components entered by the
Product
engineering department
are found in the
manufacturing BOM
9
BOM Links
New fields
10
Creating an intermediate level
Advantages of creating an intermediate level:
1 – easier description of planning rules
2 – managing an inventory is easier than managing a WIP
3 – assembly which can be common to several parent items
Disadvantages: have to manage an additional item
?
11
Rules for creating a BOM level
•
Rules:
1 - minimize the number of levels
2 - create a sub-assembly only if
inventory
can exist
3 - create a sub-assembly if there is a
break in the production
stream
4 - create a sub-assembly if there is an
independent
demand
(external requirements)
•
Practice:
–
Do not create a BOM level
when the assembly operation is
carried out as a result of the preceding operation (in the
stream)
–
Create a BOM level
at each declared manufacturing step
12
Effects of an intermediate level
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13
Phantom Items
•
Definition
–
Non-storable items (ephemeral existence)
–
Have a BOM
–
Do not have a routing
–
Cannot support sales forecast, Customer orders,
Work orders…
•
Examples of use
–
Structuring complex BOMs
–
Grouping of components common to several BOMs
–
Creation of common BOMs
14
Common BOM
•
Principle:
–
Two products having exactly the same components
can and must use a common BOM
–
Any change will concern both products
•
Example:
–
Two parts, left and right are made with one kg of material
M
–
A change (ex: using only 0,9 kg of M)
will automatically
concern both parts
•
Practice:
–
Create a phantom item to support the common BOM
15
Common BOM
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1
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1
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2
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16
Packaging BOM
•
Packaging is indicated in a link with the finished product
•
The coefficient represents the "fraction" of packaging used
by a finished product
•
Example: if you put 12 parts in a carton, the coefficient will
be 1/12 (that is 0.0833)
17
Packaging BOM
Quantity
of parent items
in the quantity of
components specified
by the coefficient
18
Link Offset
•
Object:
–
modify the requirement date calculated from the item lead time
for some components in the BOM
•
Negative Offset
–
Makes it possible to introduce a safety lead time for a particularly
sensitive component
•
Positive Offset
–
Allows to indicate that a component if not required at the release
date but at the end of the process (example: packaging)
•
Specified in days
19
Link Offset
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Another solution:
Attaching components
at each routing operation
20
BOMs changes over time
•
Object:
–
Plan for future product developments (Engineering
changes)
–
Find the composition of a product manufactured in
the past (After sales)
•
Practice:
–
Changes are identified by
•
Validity start and end dates in product structure record
•
Serial numbers or Engineering change notice
(not
supported by e-Prelude)
21
BOMs changes over time
Changes are identifies by validity
dates on product structure records
Used in the MRP process at release date
FG
C1
C21
C22
L
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v
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C1
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FG
C1
C22
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2
2
n
d
22
Mass Replacement
•
A component can be automatically
replaced by another
–
In all its where-used parent items
–
From an effective date
•
Example:
–
Replacing a purchased component
23
Options and Variants
•
Definition:
–
an option, it is one or several
additional components
–
a variant, it is one or several
different
components
•
Object
:
–
Describe slightly different products without having to
completely rewrite the BOMs
24
Options and Variants
•
Method base + options
–
Phantom items grouping common
components
•
Method base + variance
Create as many finished products as
combinations of options / variants
These methods can only be used at the
higher BOM level
•
Link selection
All the possible links are entered
Valid links are selected using the value of an
attribute
(not implemented in e-Prelude)
25
Method Base + options
FG220
FG110
Base
Base
Conv220
Conv110
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26
Method Base + variance
FG220
FG110
C1
Conv220
Conv110
B
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B
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C2
FG220
Conv220
C1
Conv220
C2
(-1)
(+1)
27
Selection of records
FG
FG
Conv220
Conv110
FG
Generic item
C1
Conv220
C2
Conv110
On each record: a selection attribute
Attr
FG-220
220
110
FG-110
Variant 220
Variant 110
28
By-product or co-product
•
Object:
–
Describe the fact that a by-product is created
when the main product is manufactured
•
Method:
–
crate the by-product as a component
–
E
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•
Example:
Produit
Material
By-product
C
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f
.
:
2
,
5
C
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f
.
:
-
1
When planning 1000 products
- a need for 2500 is created on the
material
- a negative requirement of 1000 is
created on the by-product which gives
rise to an inventory receipt
29
BOM Variants
•
A parent item has necessarily at least
one
Manufacturing
BOM (M)
–
Used in the MRP process
•
You can create one or more variants of M BOMs
–
Can be used to update requirements of a planned order
–
Select a name in the variant list table (Engineering menu)
–
A BOM variant is linked to a routing
•
Examples
–
A component is purchased instead of being manufactured
–
Temporary transfer of work load to a contractor
30
BOM Variants
•
Method
–
Create BOM Variant Table
(menu
Engineering
, option
BOM Variant Table
)
–
Create for each variant, the item BOM (
Bill of Materials
Maintenance
page)
–
Assign a BOM variant to Item routings (
Item Maintenance
page,
Routing
grid)
•
The planning process will take into account the item
release routing and the BOM variant attached
31
BOM Variant Selection
32
Specifying BOM Variants
For each routing, it is possible
to attach a BOM variant
33
BOM Variants
(another solution)
•
Create Phantom items as parent items
•
Create BOM variants for each Phantom item
•
Attach one of these phantom items to the
manufactured item
–
permanently (BOM of manufactured item)
–
temporarily (for one work order)
34
BOM Variants
(another solution)
Manufactured item
Variant 1
Variant 2
C1
C2
C3
A1
C2
C’3
Phantoms
35
Attaching components to
each operation
M
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M
a
t
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a
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1
M
a
t
e
r
i
a
l
2
S
/
A
It is indicated to which routing operation the component is used
This information is used for
•
Planning components requirements
•
Components backflush at each operation
Manufacturing routing
36
Attaching components to each
operation
Nouvelle zone
37
Attaching components to
each operation
Op. 010
Op. 020
Op. 030
Op. 040
WO Due Date
WO Release Date
Due date
for components
attached
to operation 040
Due date
for components
attached
to operation 030
Due date
for components
attached
to operation 020
Due date
for components
attached
to operation 010
and components
Not attached
to any operation
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38
Effects on Production Cycle
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Production Cycle
Production Cycle
Bills of Materials (BOM) play a crucial role in technical data management, recording the components needed for product creation and manufacturing processes. This content discusses the types of BOM, decimals used in BOM links, components to include in BOMs, BOM creation, and structures of Engineering and Manufacturing BOMs.
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Presentation Transcript
e-Prelude.com Technical Data Management Bills of Materials 1
Bills of Materials Content BOM types Intermediate Level Creation Phantom Items Common BOM Link Offset BOM evolution By-products and co-products BOM Variants Linking components to routing operation 2
BOM decimals For each item, the number of decimals used for the coefficient of its BOM links should be specified Examples: Assembled product: 0 decimal Only an integer number of components can be mounted chemical combination: 4 decimals 0.0253 kg for a component 3
Which components should be recorded in the BOMs? Should be recorded in the bills of materials all materials and all components including waste packaging Should NOT be recorded in the bills of materials components with erratic consumption and/or with a very low cost examples: oil, stretch films, tags recyclable packaging examples: containers, pallets, ... 4
BOM types Engineering BOM created by the Product engineering department Used during product design phases and development (up to prototyping) Manufacturing BOM created by the Process engineering department maintained by the plants Budget (or Frozen) BOM Used as budget reference Created by the Frozen Data Creation function (Costing menu) Select the date for link selection Creates a copy of valid links 5
BOM types An manufactured item can have several BOMs Select the BOM type in the drop-down list 6
Engineering BOM Structure depends on Product engineering department working methods Product Breakdown usually by functions Gradual development Choices technical performance - manufacturing cost Transfer to manufacturing 7
Manufacturing BOM Structure depends on the manufacturing steps of a product Created by the Process engineering department when it enters the routings It must be verified that, at the lowest level, all the components entered by the Product engineering department are found in the manufacturing BOM 8
BOM Links New fields 9
Creating an intermediate level ? FG FG C1 C2 C3 S/A C3 C1 C2 Advantages of creating an intermediate level: 1 easier description of planning rules 2 managing an inventory is easier than managing a WIP 3 assembly which can be common to several parent items Disadvantages: have to manage an additional item 10
Rules for creating a BOM level Rules: 1 - minimize the number of levels 2 - create a sub-assembly only if inventory can exist 3 - create a sub-assembly if there is a break in the production stream 4 - create a sub-assembly if there is an independent demand (external requirements) Practice: Do not create a BOM level when the assembly operation is carried out as a result of the preceding operation (in the stream) Create a BOM level at each declared manufacturing step 11
Effects of an intermediate level Allows to grouper requirements for common sub-assemblies P1 SA1 FG P2 Receipt-Issue Transactions SA2 P3 Longer manufacturing cycle Manufacturing Cycle P1 Rake BOM (single level) P2 FG P3 ManufacturingCycle 12
Phantom Items Definition Non-storable items (ephemeral existence) Have a BOM Do not have a routing Cannot support sales forecast, Customer orders, Work orders Examples of use Structuring complex BOMs Grouping of components common to several BOMs Creation of common BOMs 13
Common BOM Principle: Two products having exactly the same components can and must use a common BOM Any change will concern both products Example: Two parts, left and right are made with one kg of material M A change (ex: using only 0,9 kg of M) will automatically concern both parts Practice: Create a phantom item to support the common BOM 14
Common BOM FG1 FG2 C1 C2 C3 C1 C2 C3 FG1 FG2 Phantom Phantom Phantom C1 C2 C3 15
Packaging BOM Packaging is indicated in a link with the finished product The coefficient represents the "fraction" of packaging used by a finished product Example: if you put 12 parts in a carton, the coefficient will be 1/12 (that is 0.0833) 16
Packaging BOM Quantity of parent items in the quantity of components specified by the coefficient 17
Link Offset Object: modify the requirement date calculated from the item lead time for some components in the BOM Negative Offset Makes it possible to introduce a safety lead time for a particularly sensitive component Positive Offset Allows to indicate that a component if not required at the release date but at the end of the process (example: packaging) Specified in days 18
Link Offset Work Order Release Date Work Order Due Date Item Lead Time Normal required component date (offset 0) Negative offset Positive offset Required component date with a negative offset Required component date of a component used at the end of the process Another solution: Attaching components at each routing operation 19
BOMs changes over time Object: Plan for future product developments (Engineering changes) Find the composition of a product manufactured in the past (After sales) Practice: Changes are identified by Validity start and end dates in product structure record Serial numbers or Engineering change notice (not supported by e-Prelude) 20
BOMs changes over time Changes are identifies by validity dates on product structure records Used in the MRP process at release date Link valid till March 21st FG Link valid from March 22nd C1 C21 C22 FG FG C1 C21 C1 C22 BOM till March 21st BOM from March 22nd 21
Mass Replacement A component can be automatically replaced by another In all its where-used parent items From an effective date Example: Replacing a purchased component 22
Options and Variants Definition: an option, it is one or several additional components a variant, it is one or several different components Object: Describe slightly different products without having to completely rewrite the BOMs 23
Options and Variants Method base + options Phantom items grouping common components Method base + variance Create as many finished products as combinations of options / variants These methods can only be used at the higher BOM level Link selection All the possible links are entered Valid links are selected using the value of an attribute (not implemented in e-Prelude) 24
Method Base + options FG220 FG110 Base Conv220 Base Conv110 FG optional component FG optional component All common components 25
Method Base + variance Base item FG220 C2 C1 Conv220 FG110 Base item variant FG220 Conv220 Conv110 (+1) (-1) C2 C1 Conv220 26
Selection of records FG Generic item C2 C1 Conv220 Conv110 On each record: a selection attribute Attr 220 110 FG-220 FG-110 FG FG Variant 220 Variant 110 Conv220 Conv110 27
By-product or co-product Object: Describe the fact that a by-product is created when the main product is manufactured Method: crate the by-product as a component Enter a negativecoefficient on the record Example: When planning 1000 products - a need for 2500 is created on the material - a negative requirement of 1000 is created on the by-product which gives rise to an inventory receipt Produit Coef. : 2,5 Coef. : -1 Material By-product 28
BOM Variants A parent item has necessarily at least one Manufacturing BOM (M) Used in the MRP process You can create one or more variants of M BOMs Can be used to update requirements of a planned order Select a name in the variant list table (Engineering menu) A BOM variant is linked to a routing Examples A component is purchased instead of being manufactured Temporary transfer of work load to a contractor 29
BOM Variants Method Create BOM Variant Table (menu Engineering, option BOM Variant Table) Create for each variant, the item BOM (Bill of Materials Maintenance page) Assign a BOM variant to Item routings (Item Maintenance page, Routing grid) The planning process will take into account the item release routing and the BOM variant attached 30
Specifying BOM Variants For each routing, it is possible to attach a BOM variant 32
BOM Variants (another solution) Create Phantom items as parent items Create BOM variants for each Phantom item Attach one of these phantom items to the manufactured item permanently (BOM of manufactured item) temporarily (for one work order) 33
BOM Variants (another solution) Manufactured item Variant 1 Variant 2 Phantoms A1 C2 C 3 C1 C2 C3 34
Attaching components to each operation Manufacturing routing Op. 010 Op. 020 Op. 030 Op. 040 Manufactured Item Material 1 S / A Material 2 It is indicated to which routing operation the component is used This information is used for Planning components requirements Components backflush at each operation 35
Attaching components to each operation Nouvelle zone 36
Attaching components to each operation WO Release Date WO Due Date Op. 010 Op. 020 Op. 030 Op. 040 Due date for components attached to operation 020 Due date for components attached to operation 030 Due date for components attached to operation 040 Due date for components attached to operation 010 and components Not attached to any operation Components Due Dates are calculated while scheduling the Work Order 37
Effects on Production Cycle P1 S/A1 FG P2 S/A2 P3 Production Cycle S/A1 P1 FG P2 P3 S/A2 Production Cycle 38
