The DES Program was developed using the framework of instructional design guidelines within a systems approach model.
system is technically a set of interrelated parts, all of which are
working together toward a defined goal. The parts of the system depend
on each other for input and output, and the entire system uses feedback
to determine if its desired goal has been reached. If it has not, then
the system is modified until it does reach the goal. The purpose of
the system is to bring about learning. The components of the system
are the learners, the instructor, the instructional materials, and the
learning environment. These components interact in order to achieve
the goal. The systems approach models are an outgrowth of more than
twenty years of research into the learning process.