The major emphasis of airline engine performance testing can be summarized by three precepts: 1. Avoid release of engines which will be maintenance problems. 2. Prevent rejection of engines which will operate satisfactorily until the next scheduled removal. 3. Reduce testing costs. This paper will present the methods used by United Air Lines to most profitably assign relative weights to the three guidelines. Further, in a related but somewhat diverse section, progress with an automated test cell data acquisition system will be presented.