Page 298 - Mechanical Engineers' Handbook (Volume 2)

5 System Design 289

10. To determine typical planning horizons and periods to which the system or systemic
process must be responsive
11. To determine the extent of tolerable operational environment alteration due to use
of the system or systemic process
12. To determine what particular planning, design, or decision process appears best
13. To determine the most appropriate roles for the system or systemic process to per-
form within the context of the planning, design, or decision situation and operational
environment under consideration
14. To estimate potential leadership requirements for use of the final system itself
15. To estimate user group training requirements
16. To estimate the qualifications required of the design team
17. To determine preliminary operational evaluation plans and criteria
18. To determine political acceptability and institutional constraints affecting use of an
aided support process and those of the system itself
19. To document analytical and behavioral specifications to be satisfied by the support
process and the system itself
20. To determine the extent to which the user group can require changes during and
after system development
21. To determine potential requirements for contractor availability after completion of
development and operational tests for additional needs determined by the user
group, perhaps as a result of the evaluation effort
22. To develop requirements specifications for prototype design of a support process
and the operational system itself
As a result of this phase, to which the four issue requirements identification approaches
of Section 4.1 are fully applicable, there should exist a clear definition of typical planning,
design, and decision issues, or problems requiring support, and other requirements specifi-
cations, so that it is possible to make a decision whether to undertake preliminary conceptual
design. If the result of this phase indicates that the user group or client needs can potentially
be satisfied in a cost-effective manner, by a systemic process aid, for example, then docu-
mentation should be prepared concerning detailed specifications for the next phase, prelim-
inary conceptual design, and initial specifications for the last three phases of effort. A design
team is then selected to implement the next phase of the system life cycle. This discussion
emphasizes the inherently coupled nature of these phases of the system life cycle and illus-
trates why it is not reasonable to consider the phases as if they are uncoupled.
Preliminary Conceptual Design and Architecting Phase
The preliminary conceptual design and architecting phase includes specification of the math-
ematical and behavioral content and associated algorithms for the system or process that
should ultimately result from the effort as well as the possible need for computer support to
implement these. The primary goal of this phase is to develop conceptualization of a pro-
totype system or process in response to the requirements specifications developed in the
previous phase. Preliminary design according to the requirements specifications should be
achieved. Objectives for preliminary conceptual design include the following:
1. To search the literature and seek other expert opinion concerning the particular ap-
proach to design and implementation that is likely to be most responsive to
requirements specifications