One way to achieve cost justification is to do a cost and benefits evaluation based on each type of test. When quantity is limited from a few boards to maybe 50 or so, a good PCB testing solution could be flying probe, whereas if the quantity is higher, generally speaking, in-circuit test (ICT) is a good choice.
Cost of manufacturing ICT fixtures ranges from a few thousand to over $50,000, and justification is demanded for making these dollar outlays. That’s when the number of product shipments factors in. If an EMS provider is shipping 50 to 100 boards a month to an OEM, for example, and it is determined that the product’s lifecycle is expected to be at least two years or more, then the cost of this expensive ICT fixture could be amortized over that time period. Keeping all other incidental costs in mind, the incremental cost of the fixture per board supplied is relatively small.
On the other hand, if monthly shipments in terms of number of PCBs are relatively large, say 250 to 300 boards per shipment, then amortization would not even take two years. Hence, the entire cost of manufacturing such an expensive ICT fixture could be amortized in less than a year. Therefore, amortization depends on ICT fixture manufacturing cost and the number of shipments scheduled for an extended time period.