[This set of inputs [can be defined] as 1) input which is always the same or is of many types, 2) input which occurs periodically (or very infrequent… - Robert E. Machol

There are four distinct bases on which a system-design book might be organized. First are the chronological phases through which the system-design effort passes, such as organization and preliminary design. Second are the logical steps such as analysis of the single thread (operation on a single input) and high traffic (methods of handling multiplex inputs). Third are the parts of the system, such as communications and displays. Fourth are the tools of system design, such as information theory and queueing theory.

The ideal system engineer is an engineer thoroughly versed in his field but conversant with and knowledgeable of other fields. You have to have the capability and desire to become a 'six-month expert'... You've got to want to become a generalist, too.

Every large-scale system is an . The automatic factory, the vehicular-traffic system, any military system- in the design of all these systems, primary attention should be given to the flow of information about the elements of the system.