A manufacturing execution system determines production rates of tool elements of a manufacturing system and from the production rates, the efficiency of the tool elements and the efficiency of the manufacturing process system. The probe head structure includes a guide plate and a template and supports a plurality of test probes that each includes a tip portion with a tip end for making electrical contact with a device under test, a curved compliant body portion and a tail portion with a tail end for making electrical contact with the space transformer. A second recess portion is provided on the other of the first and second cases, and receives a remaining part of the female-female terminal.