Page 269 - Mechanical Engineers' Handbook (Volume 2)

260 Analysis, Design, and Information Processing

• The systems management issues associated with choice of an appropriate process
• Organizations and humans and the understanding of organizational and human behav-
ior
• Environments and understanding of the diverse interactions of organizations of people,
technologies, and institutions with their environments
• Information and the way in which it can and should be processed to facilitate all
aspects of systems engineering efforts
Successful systems engineering must be practiced at three levels: systems methods and
measurements, systems processes and methodology, and systems management. Systems en-
gineers must be aware of a wide variety of methods that assist in the formulation, analysis,
and interpretation of contemporary issues. They must be familiar with systems engineering
process life cycles (or methodology, as an open set of problem-solving procedures) in order
to be able to select eclectic approaches that are best suited to the task at hand. Finally, a
knowledge of systems management is necessary in order to be able to select life-cycle
processes that are best matched to behavioral and organizational concerns and realities.
All three of these levels, suggested in Fig. 1, are important. To neglect any of them in
the practice of systems engineering is to invite failure. It is generally not fully meaningful
to talk only of a method or algorithm as a useful system-fielding or life-cycle process. It is
ultimately meaningful to talk of a particular process as being useful. A process or product
line that is truly useful for the fielding of a system will depend on the methods that are
available, the operational environment, and leadership facets associated with use of the sys-
tem and the system-fielding process. Thus systems management, systems engineering proc-
esses, and systems engineering methods and measurements do, separately and collectively,
play a fundamental role in systems engineering.

2 THE SYSTEM LIFE CYCLE AND FUNCTIONAL ELEMENTS
OF SYSTEMS ENGINEERING

We have provided one definition of systems engineering thus far. It is primarily a structural
and process-oriented definition. A related definition, in terms of purpose, is that ‘‘systems

Figure 1 Conceptual illustration of the three levels for systems engineering.