Reverse engineering a printed circuit board (PCB) is the process of taking an existing board and creating a schematic diagram and a bill of materials (BOM) for it. This process is useful when the original design files are unavailable or incomplete, and the board needs to be replicated, repaired, or modified.

A circuit board Bill of Materials (BOM) is a comprehensive list of all the components that are required to assemble a particular printed circuit board (PCB). This list is a vital part of the design process and ensures that the PCB is assembled accurately, and to the desired specification. The circuit board BOM contains information about the components' specifications, quantities, and suppliers. It is the backbone of the manufacturing process, as it guides the procurement of all the components required to build the PCB.