Introduction Manufacturing test engineers often face the challenge of testing multiple UUT’s (Units Under Test) on a single functional test system. Testing a single UUT functionally is hard enough, and testing more than one UUT on a single test system simply adds to the problem. Even so, there are often good reasons to test multiple UUT’s at once. Sometimes there is a requirement to do s for example, modern PCB manufacturing often results in multiple boards physically built on the same panel for reasons of cost. In this case, the test system needs to be able to deal with multiple UUT’s. Testing multiple UUT’s at once can also frequently help reduce the cost of test equipment requiredto match a particular manufacturing capacity by increasing test throughput per UUT and increasing test system utilization.