Bill of Materials Example

The following bill of materials example shows how this is constructed, using a multi level bill of materials.

The drawing above shows an example trolley for moving heavy items. Though our example may not be the best designed trolley around, it is simplified to show off the different assemblies and raw materials. The example also shows how the bill of materials can easily be modified due to a change in the design.

bill of materials

In this bill of materials example we will start at the top level, and drill our way down to the individual components. To simplify things in this example, the bill of materials has some basic information omitted e.g. cost for clarity. Also to keep things simple, the bill of materials has a maximum of 4 levels deep.

At the top level there are only two different parts:

Example 1
LevelPart NoDescriptionGroupUnitQTYWaste %Ext QTY
1120-001Trolley, 3 wheeledAssyEA1.00000.00001.0000
 2112-001Plywood PlatformPartEA1.00000.00001.0000
 2110-001Wheel HousingAssyEA3.00000.00003.0000

For the plywood platform, this is quite simple and has a separate bill of materials. under part no. 112-001.

Example 2
LevelPart NoDescriptionGroupUnitQTYWaste %Ext QTY
1112-001Plywood PlatformPartEA1.00000.00001.0000
 2106-001Plywood,12mm,2400x1200RMSH0.12500.00000.1250
 2111-006Varnish, Semi GlossPRL0.05000.10000.0501
 2130-001LaborLBHR0.65000.00000.6500

With the bill of materials above the assembly contains all the raw materials and labor to manufacture that part.

The wheel assembly also has a bill of materials, but has a quantity of 3

Example 3
LevelPart NoDescriptionGroupUnitQTYWaste %Ext QTY
1110-001Wheel HousingAssyEA3.00000.00003.0000
 2110-003Side PiecePartEA2.00000.00002.0000
 2110-002Top PiecePartEA1.00000.00001.0000
 2102-108Wheel, with tyre, 100mmPartEA1.00000.00001.0000
 2100-001MS Bolt, M10x70, GalvFastEA1.00000.00001.0000
 2100-002M10, washer, GalvFastEA2.00000.00002.0000
 2100-003M10, Nut, GalvFastEA3.00000.00003.0000
 2100-004MS Bolt, M10x30, GalvFastEA1.00000.00001.0000
 2100-005M10 Square NutFastEA1.00000.00001.0000

This assembly has a number of raw materials, but also two parts, each which have a further bill of materials, the top piece & side piece.

The Side piece part is used twice in the wheel housing, and the top piece part is used once.

The Side piece bill of materials is listed below:

Example 4
LevelPart NoDescriptionGroupUnitQTYWaste %Ext QTY
1110-003Side PiecePartEA2.00000.00002.0000
 2105-001MS Flat 80x8RMM0.10005.00000.1050
 2111-001GalvanisingPRKG0.00100.00000.0010
 2130-000LaborLBHR0.10000.00000.1000

And likewise the top piece bill of material is listed below:

Example 5
LevelPart NoDescriptionGroupUnitQTYWaste %Ext QTY
1110-002Top PiecePartEA1.00000.00001.0000
 2105-001MS Flat 80x8RMM0.05005.00000.0525
 2111-001GalvanisingPRKG0.00100.00000.0010
 2130-000LaborLBHR0.50000.00000.5000

When the multi level entire wheel assembly is put together, we use the list from example 3, but as the top piece and side piece have their own separate bill of materials, the levels of all the parts used in examples 4 & 5 are carried down one. The entire bill of materials for the wheel assembly is listed below:

Example 6
LevelPart NoDescriptionGroupUnitQTYWaste %Ext QTY
1110-001Wheel HousingAssyEA3.00000.00003.0000
 2110-003Side PiecePartEA2.00000.00002.0000
  3105-001MS Flat 80x8RMM0.10005.00000.1050
  3111-001GalvanisingPRKG0.00100.00000.0010
  3130-000LaborLBHR0.10000.00000.1000
 2110-002Top PiecePartEA1.00000.00001.0000
  3105-001MS Flat 80x8RMM0.05005.00000.5250
  3111-001GalvanisingPRKG0.00100.00000.0010
  3130-000LaborLBHR0.50000.00000.5000
 2102-108Wheel, with tyre, 100mmPartEA1.00000.00001.0000
 2100-001MS Bolt, M10x70, GalvFastEA1.00000.00001.0000
 2100-002M10, washer, GalvFastEA2.00000.00002.0000
 2100-003M10, Nut, GalvFastEA3.00000.00003.0000
 2100-004MS Bolt, M10x30, GalvFastEA1.00000.00001.0000
 2100-005M10 Square WasherFastEA1.00000.00001.0000

When the entire bill of materials is put together, combined with the plywood platform, all the levels in the wheel assembly again move down a level.

Example 7
LevelPart NoDescriptionGroupUnitQTYWaste %Ext QTY
1120-001Trolley, 3 wheeledAssyEA1.00000.00001.0000
 2112-001Plywood PlatformPartEA1.00000.00001.0000
  3106-001Plywood,12mm,2400x1200RMSH0.12500.00000.1250
  3111-006Varnish, Semi GlossPRL0.05000.10000.0501
  3130-001LaborLBHR0.65000.00000.6500
 2110-001Wheel HousingAssyEA3.00000.00003.0000
  3110-003Side PiecePartEA2.00000.00002.0000
   4105-001MS Flat 80x8RMM0.10005.00000.1050
   4111-001GalvanisingPRKG0.00100.00000.0010
   4130-000LaborLBHR0.10000.00000.1000
  3110-002Top PiecePartEA1.00000.00001.0000
   4105-001MS Flat 80x8RMM0.05005.00000.0525
   4111-001GalvanisingPRKG0.00100.00000.0010
   4130-000LaborLBHR0.50000.00000.5000
  3102-108Wheel, with tyre, 100mmPartEA1.00000.00001.0000
  3100-001MS Bolt, M10x70, GalvFastEA1.00000.00001.0000
  3100-002M10, washer, GalvFastEA2.00000.00002.0000
  3100-003M10, Nut, GalvFastEA3.00000.00003.0000
  3100-004MS Bolt, M10x30, GalvFastEA1.00000.00001.0000
  3100-005M10 Square NutFastEA1.00000.00001.0000

If you see from the example above, it is easy to change the bill of materials should the quantity change from a three wheel to a four wheel design, by simply adjusting the quantities associated with the plywood platform and the wheel housing (part 110-001) from a quantity of 3 to 4

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