Minimizing Production Costs Through Modular Automatic Test Equipment

Abstract

The dominant consideration influencing the trend toward automatic test and checkout techniques for production-line test stations is cost reduction. Testing costs include the costs of test equipment and spares, of operating and maintaining personnel, of floor space, and of down time. As test cost per unit produced is the basis for comparison, the test rate achieved per station is a major factor. An analysis of test station requirements for a mass-produced missile is used as an example. This analysis shows major reductions in test cost per unit as a result of automation for subassemblies which have fairly complex test requirements; whereas for simple subassemblies, there are no cost improvements and manual testing is quite satisfactory. The necessity for maintaining high test rates with fewer, less skilled operators and with the corresponding reduction in test-stations imposes high reliability requirements on automated equipment in order to preserve this economic advantage. Therefore, such features as self-checking, fail-safe design, and printed-out test results are essential. The construction of automatic test sets from functional universal modules reduces first cost of equipment, permits rapid and economic servicing, and reduces obsolescence of equipment. Another advantage of the modular approach to production-line test set design is that test sets using only a low order of automation may utilize modules identical to those of the fully automated equipment. This extends the ``break-even'' point in the choice between automated and manual equipment towards increased application of the more sophisticated techniques.