1. 1 Bill of Materials In a production control environment, a bill of materials (BOM) is a data model used to represent the relationship of a part to another part. Suppose we produce and sell bicycles. Suppose further that we have a certain bicycle named ExtremeCycle101, and that the parts that go into producing this type of bike can be partly illustrated as shown below.

2. 2 ExtremeCycle101 HandleBarX FrameXSeatB919Wheel111 Frame101PedalZ1Rim120Spoke12.

3. 3 The diagram above informs us that an ExtremeCycle101 I an assembly (it has component parts) that is constructed from those types of parts shown at the second level (HandleBarX, FrameX, SeatB919, Wheel111, …). HandleBarX is a part, it is not an assembly. Note that FrameX is another assembly made from a specific frame and pedals. The type of diagram shown above is called a parts explosion; it can show in great detail the various part that are required to build the part shown at the top, at the root. In some enterprise, a parts explosion could detail hundreds or thousands of parts. Another common way to illustrate this information is in a table such as:

4. 4 PartComponentQuantity ExtremeCycle101HandleBarX1 ExtremeCycle101FrameX1 ExtremeCycle101SeatB9191 ExtremeCycle101Wheel1112 FrameXFrame1011 FrameXPedalZ12 Wheel111Rim1201 Wheel111Spoke1221