Figure B-1 shows a series of blocks that represent sub-systems of the main system. For example, it shows a Display Computer comprising of a SCS1 MPU, Radar Display Computer (2 off), Flight Strip Printer, Flight Data Processor Timing Unit and Workstation.

The correct identification of these sub-systems is an important aspect of the RBD. Each sub-system would normally be limited to a list of Line Replaceable Units (LRUs) to enable the calculation of the sub-system failure rate.

RBDs are not intended to emulate the technical layout of the system. Therefore, the order in which sub-systems are placed on the diagram is irrelevant.