A MODEL IS CONSTRUCTED TO DETERMINE THE BEST PROPORTION OF FORMAL AND ON-THE-JOB TRAINING IN MILITARY OCCUPATIONS. SPECIAL CONSIDERATION IS GIVEN TO THE UNIQUE SITUATION OF ENLISTED PERSONNEL'S FIXED LENGTH OF SERVICE, THE SMALL PERCENTAGE OF RE-ENLISTMENT, AND THE NECESSITY OF TRAINING ALL ENLISTEES FOR ASSIGNED OCCUPATIONS. THE MODEL FORMULA REPRESENTS TRAINING REQUIREMENTS, SEMISKILLED AND SKILLED LEVELS, AMOUNT OF TIME SPENT AT EACH SKILL LEVEL (DETERMINED BY FORMAL OR ON-THE-JOB TRAINING), AND COST REDUCTION POSSIBLE WITHOUT REDUCTION OF THE LEVEL OF EFFECTIVENESS. ANALYSIS IS APPLIED TO TEN AIR FORCE OCCUPATIONS INCLUDING COOK, AUTOMOTIVE REPAIRMAN, ELECTRICIAN, AND PERSONNEL AND ADMINISTRATIVE SPECIALISTS. RESULTS ARE SHOWN IN SIX TABLES. COSTS ARE GENERALLY LOWER FOR ON-THE-JOB TRAINING, BUT ENLISTEES REMAIN AT THE SEMISKILLED LEVEL LONGER THAN FORMALLY TRAINED ENLISTEES. THIS DOCUMENT APPEARED IN MANPOWER PLANNING, OPERATION RESEARCH AND PERSONNEL RESEARCH, EDITED BY W.N. JESSOP. IT IS AVAILABLE FROM AMERICAN ELSEVIER PUBLISHING COMPANY, INC., 52 VANDERBILT AVENUE, NEW YORK, N.Y., 10017. 16 PAGES. (PT)