Single Level Example

A single level bill of materials is easier to understand, its like a straightforward shopping list of all the parts used in a construction. Unfortunately if it used to construct a bill of materials it can be prone to errors, except from the simplest of assemblies. A single level bill of materials can be automatically generated from a multi level bill of materials, but not vice versa.

From our trolley example, a bill of materials is listed below:

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,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	2.7500	0.0000	0.6500
2	110-001	Side Piece	Part	EA	2.0000	0.0000	2.0000
2	105-001	MS Flat 80×8	RM	M	0.7500	5.0000	0.0525
2	111-001	Galvanising	PR	KG	0.0090	0.0000	0.0010
2	102-108	Wheel, with tyre, 100mm	Part	EA	3.0000	0.0000	1.0000
2	100-001	MS Bolt, M10x70, Galv	Fast	EA	3.0000	0.0000	1.0000
2	100-002	M10, washer, Galv	Fast	EA	6.0000	0.0000	2.0000
2	100-003	M10, Nut, Galv	Fast	EA	9.0000	0.0000	3.0000
2	100-004	MS Bolt, M10x30, Galv	Fast	EA	3.0000	0.0000	1.0000
2	100-005	M10 Square Nut	Fast	EA	3.0000	0.0000	1.0000

If you see from the example above, it is a lot harder and slower to change the bill of materials should the quantity change from a three wheel to a four wheel design, compared to the multi level bill of materials example. Also to change from a three to four wheel design it is much easier to make a mistake.