Advanced application of the printed circuit board testability design and rating system

The objectives of this study were to extend the present PCB testability design and rating system developed by Grumman to the module, rack, and subsystem levels and to generate an overall system level testability figure of merit (FOM). The FOM developed is based on the evaluation of a system, modelled as a node-valued weighted graph, (a node being each individual PCB in the system). This model requires as inputs the testability ratings of each individual PCB (outside the system) as a number between 0 and 1. This FOM was validated on 3 of Boeing Aerospaces' own subsystems, each containing a various number of PCB's. The results of the validation and the development of the FOM model are presented. This model has been computerized in the PASCAL computer language and is provided as part of this report.