To assist planners of instructional media systems, a combination of analytical and synthetical processes are being devised. This "kit of tools" is really a model of Instructional System Design, not a model of any particular instructional system. The policy-making process is displayed in a table and then explained. The communication media to be considered are shown in another table which is self-explanatory. A flow chart illustrates the process of choosing a media class. Next to be completed is a formulation of rules for media system design and an assemblage of cost-estimating relationships. The model being developed may be extended to such functions as class scheduling and curriculum planning. (MF)