Operational Criteria for Automatic Missile Readiness Testing

One of the activities in which automatic testing plays a key role is missile readiness testing, which is that set of tests performed regularly for the purpose of detecting failures that have occurred in the missile and launch equipment. This is done in order to maintain a high state of operational readiness, measured in terms of readiness probability. An important adjunct to criteria for physical characteristics of readiness-testing techniques and equipment are statements derived from operational analyses that specify 1) what tests are done best by each testing method, 2) the best test frequencies, and 3) the preferred equipment locations for each test; these are operational design criteria and they depend greatly upon the obtainable readiness probability. Depending on the test techniques employed, different testing methods (check periodically, monitor continuously, leave alone) and equipment locations (van, silo, missile) could yield different readiness probabilities for each missile subsystem. These probabilities depend on the particular missile's characteristics (test-point availability, failure rates, modes of operation, etc.) and test technique and equipment characteristics (test completeness, accuracy, failure rates, etc.). In addition, missile system concepts or constraints such as fixed periods for some inspections and planned delays before repair must be accounted for in the readiness determination. Using probabilistic models to describe the system operation, computational forms are developed that account for each of the above physical and operational factors, and estimate the readiness probability of either an entire missile or each of its parts.