To assist managers of complex training systems in making decisions that result in changes in the existing training syllabus, this study provides a model for estimating and comparing the costs of training system components and of potential changes to the components. In the first part of the study, this assessment model is broken down into five principal cost categories: (1) instructional systems development (ISD), (2) facilities, (3) training devices, (4) actual equipment trainers (AET), and (5) students. The model is then applied to data available from the P-3 (land-based antisubmarine warfare fixed-wing aircraft) fleet readiness squadron (FRS) aircrew training system. Cost comparisons reveal that ISD costs are minor (1 percent) compared to the total cost of aircrew training. The costs attributable to AET constitute the bulk (75 percent) of the total costs. Second in importance to AET costs is the cost of students (15 percent). The remaining costs of facilities and training devices are 1.5 percent and 7.6 percent, respectively. The study recommends the use of cost assessments prior to training system acquisition or revision. Included are 23 tables of data on P-3 related training system costs. (JBM)