Bill of Materials Example - Bill of Materials (BOM)

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, raw materials. The example also shows how the bill of materials can easily be modified due to a change in the design.

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

Level	Part No	Description	Group	Unit	QTY	Waste %	Ext QTY
1	120-001	Trolley, 3 wheeled	Assy	EA	1.0000	0.0000	1.0000
2	112-001	Plywood Platform	Part	EA	1.0000	0.0000	1.0000
2	110-001	Wheel Housing	Assy	EA	3.0000	0.0000	3.0000

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

Example 2

Level	Part No	Description	Group	Unit	QTY	Waste %	Ext QTY
1	112-001	Plywood Platform	Part	EA	1.0000	0.0000	1.0000
2	106-001	Plywood,12mm,2400×1200	RM	SH	0.1250	0.0000	0.1250
2	111-006	Varnish, Semi Gloss	PR	L	0.0500	0.1000	0.0501
2	130-001	Labor	LB	HR	0.6500	0.0000	0.6500

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

Level	Part No	Description	Group	Unit	QTY	Waste %	Ext QTY
1	110-001	Wheel Housing	Assy	EA	3.0000	0.0000	3.0000
2	110-001	Side Piece	Part	EA	2.0000	0.0000	2.0000
2	110-002	Top Piece	Part	EA	1.0000	0.0000	1.0000
2	102-108	Wheel, with tyre, 100mm	Part	EA	1.0000	0.0000	1.0000
2	100-001	MS Bolt, M10x70, Galv	Fast	EA	1.0000	0.0000	1.0000
2	100-002	M10, washer, Galv	Fast	EA	2.0000	0.0000	2.0000
2	100-003	M10, Nut, Galv	Fast	EA	3.0000	0.0000	3.0000
2	100-004	MS Bolt, M10x30, Galv	Fast	EA	1.0000	0.0000	1.0000
2	100-005	M10 Square Nut	Fast	EA	1.0000	0.0000	1.0000

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

Level	Part No	Description	Group	Unit	QTY	Waste %	Ext QTY
1	110-001	Side Piece	Part	EA	2.0000	0.0000	2.0000
2	105-001	MS Flat 80×8	RM	M	0.1000	5.0000	0.1050
2	111-001	Galvanising	PR	KG	0.0010	0.0000	0.0010
2	130-000	Labor	LB	HR	0.1000	0.0000	0.1000

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

Example 5

Level	Part No	Description	Group	Unit	QTY	Waste %	Ext QTY
1	110-002	Top Piece	Part	EA	1.0000	0.0000	1.0000
2	105-001	MS Flat 80×8	RM	M	0.0500	5.0000	0.0525
2	111-001	Galvanising	PR	KG	0.0010	0.0000	0.0010
2	130-000	Labor	LB	HR	0.5000	0.0000	0.5000

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

Level	Part No	Description	Group	Unit	QTY	Waste %	Ext QTY
1	110-001	Wheel Housing	Assy	EA	3.0000	0.0000	3.0000
2	110-001	Side Piece	Part	EA	2.0000	0.0000	2.0000
3	105-001	MS Flat 80×8	RM	M	0.1000	5.0000	0.1050
3	111-001	Galvanising	PR	KG	0.0010	0.0000	0.0010
3	130-000	Labor	LB	HR	0.1000	0.0000	0.1000
2	110-002	Top Piece	Part	EA	1.0000	0.0000	1.0000
3	105-001	MS Flat 80×8	RM	M	0.0500	5.0000	0.5250
3	111-001	Galvanising	PR	KG	0.0010	0.0000	0.0010
3	130-000	Labor	LB	HR	0.5000	0.0000	0.5000
2	102-108	Wheel, with tyre, 100mm	Part	EA	1.0000	0.0000	1.0000
2	100-001	MS Bolt, M10x70, Galv	Fast	EA	1.0000	0.0000	1.0000
2	100-002	M10, washer, Galv	Fast	EA	2.0000	0.0000	2.0000
2	100-003	M10, Nut, Galv	Fast	EA	3.0000	0.0000	3.0000
2	100-004	MS Bolt, M10x30, Galv	Fast	EA	1.0000	0.0000	1.0000
2	100-005	M10 Square Washer	Fast	EA	1.0000	0.0000	1.0000

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

Level	Part No	Description	Group	Unit	QTY	Waste %	Ext QTY
1	120-001	Trolley, 3 wheeled	Assy	EA	1.0000	0.0000	1.0000
2	112-001	Plywood Platform	Part	EA	1.0000	0.0000	1.0000
3	106-001	Plywood,12mm,2400×1200	RM	SH	0.1250	0.0000	0.1250
3	111-006	Varnish, Semi Gloss	PR	L	0.0500	0.1000	0.0501
3	130-001	Labor	LB	HR	0.6500	0.0000	0.6500
2	110-001	Wheel Housing	Assy	EA	3.0000	0.0000	3.0000
3	110-001	Side Piece	Part	EA	2.0000	0.0000	2.0000
4	105-001	MS Flat 80×8	RM	M	0.1000	5.0000	0.1050
4	111-001	Galvanising	PR	KG	0.0010	0.0000	0.0010
4	130-000	Labor	LB	HR	0.1000	0.0000	0.1000
3	110-002	Top Piece	Part	EA	1.0000	0.0000	1.0000
4	105-001	MS Flat 80×8	RM	M	0.0500	5.0000	0.0525
4	111-001	Galvanising	PR	KG	0.0010	0.0000	0.0010
4	130-000	Labor	LB	HR	0.5000	0.0000	0.5000
3	102-108	Wheel, with tyre, 100mm	Part	EA	1.0000	0.0000	1.0000
3	100-001	MS Bolt, M10x70, Galv	Fast	EA	1.0000	0.0000	1.0000
3	100-002	M10, washer, Galv	Fast	EA	2.0000	0.0000	2.0000
3	100-003	M10, Nut, Galv	Fast	EA	3.0000	0.0000	3.0000
3	100-004	MS Bolt, M10x30, Galv	Fast	EA	1.0000	0.0000	1.0000
3	100-005	M10 Square Nut	Fast	EA	1.0000	0.0000	1.0000

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