A BOM displays its information in one of two ways: an explosion display or an implosion display. An explosion display defines an assembly at the highest level broken down into individual components and parts. A BOM implosion display links the lower-level parts to an assembly at the higher level.
For example, a computer is exploded into hard drives, chips, random access memory panels, and processors. Each processor is then exploded into an arithmetic unit, a control unit, and a register. The requirements for the arithmetic unit, control unit, and register are imploded into the requirements for the processor, which are imploded into the requirements for the computer.