Modeling the Interrelationships
At some point in the decision-making process the various elements must be brought together.
The objective, the relevant data, the feasible alternatives and the selection criterion must be
merged. The relationships may be obscure and complex, as in trying to measure the impact of a
domestic decision on world peace. They may be impossible to define on paper in any meaningful
way. On the other hand, if one were considering borrowing money to pay for an automobile, for
example, there is a readily defined mathematical relationship between the following variables:
amount of the loan, loan interest rate, duration of the loan, and monthly payment.
The construction of the interrelationships between the decision-making elements is frequently
called model building or construction of the model. To an engineer, modeling may be of two
forms: a scaled physical representation of the real thing or system; or a mathematical equation, or
set of equations, that describe the desired interrelationships. In a laboratory there may be a
physical model, but in decision-making the model is mathematical. In modeling it is usual to
represent only that part of the real system that is important to the problem at hand. Thus, the
mathematical model of the student capacity of a classroom might be
Capacity = lw/k;
where l = length of classroom in meters, w = width of classroom in meters, and K = classroom
arrangement factor.
K factor:
- 0.6 Auditorium seating
- 1.7 Classroom
- 3.2 Design/drafting room
- 10.0 Electronics laboratory
The equation for student capacity of a classroom is a very simple model; yet it may be adequate
for the problem being solved. Other situations might have much more elaborate mathematical
models.
This page was created by Timothy N. Burcham on 02/25/97 and was last updated on 02/25/97. The URL for this page is { }.