It is suggested that procedures for designing instructional systems which use the job inventory method to collect occupational data from incumbent workers and job supervisors can, in the data analysis phase, provide information for making decisions on cost effective scheduling of formal school training. Two situations substantiate this assertion. One situation describes correlation relationships between task factor ratings (measuring work requirements at the job site) which dictate that formal school training should be scheduled prior to job assignment. The second situation reveals relationships which allow formal school training to be delayed indefinitely. The results of three occupational studies (involving detention officers, sheriff's deputies, and police field sergeants) are reviewed to demonstrate sample applications. The studies reveal that uniform relationships do not exist for work requirements in similar occupations and indicate that unique conditions in the work environment affect relationships among work requirements. (Author/GDC)