Information Technology Reference
In-Depth Information
debugging and the need for thorough QA. An innocent syntactic (“=”
instead of “==”) or semantic (incorrect placement of parenthesis in a
mathematical expression) construct that is overlooked during coding and
subsequent QA can result in bringing the entire accounting system of an
organization to a grinding halt, affecting payrolls of all employees.
•
The system is an entity that maintains its existence
and functions as a whole through the interaction of
its parts. The behavior of different systems depends
on how the parts are related, rather than on the parts
themselves. Therefore, you can understand many
different systems using the same principles.
•
The properties of a system are the properties of the
whole. …These whole system properties are called
emergent properties — they emerge when the
whole system is working.
•
Detail complexity means there is a great number of
different parts.
•
Dynamic complexity means there is a great number
of possible connections between the parts, because
each part may have a number of different states.
•
Systems thinking is thinking in circles rather than in
straight lines. The connections between parts form
feedback loops. Feedback is the output of the system
reentering as its input, or the return of information
to influence the next step.
•
Expect time delay between cause and effect in sys-
tems. The feedback loop takes time to complete. The
more complex the system the longer the feedback
may take to appear. Time delays, if not taken into
account, can lead to overshoot and oscillation.
—From
The Art of Systems Thinking
, Joseph O'Connor
and Ian McDermott
