Functional gear testing could be defined as a series of tests that simulate the intended function of the product in an effort to determine whether an assembly operates within a specified performance range
If someone tells you his leak test system is superior because of its control software, kick the tires, so to speak. In many, if not most, applications, it is the hardware, not the software, that makes or breaks the ability to get high throughput without compromising gauge R&R.
A guided harness assembly and test system makes sure that assemblers insert wires correctly by giving them instant feedback. If wiring errors can be detected when and where they occur, preferably by the assemblers, then quality goes up while overall cost is driven down.