Complex Systems: How to Change Them
Introduction
Donella Meadows (1941-2001) was a scientist concerned with the environment
and a leading exponent for and scholar of the sustainability movement.
Donealla developed a method for intervening in a system to make change. Her
analysis utlised water resources because of her passionate interest in
sustainability, but there may be general lessons that apply to any system.
Meadows analyisis invovles 12 steps. These steps are called leverage points
because in complex systems (such as a firm, a city, an economy, a living
"small shift in one thing can produce big changes in everything". (This, it might
be observed, has similarity to Goldratt’s theory of constraints).
While some people were aware of these points, at least intuitively, they often
adjusted them in the wrong direction. Understanding how these points worked
was vital for intervening positively in the system. Such insight could be
deployed to a wide range of global problems such as economic stagnation,
poverty, environmental degradation and resource depletion.
Meadow’s analysis of a system views it as containing a stock. There are
inflows (things going into the system) and outflows (things going out of the
system). Those who seek to change the system have a goal which constitues a
desired state. The difference between this desired state of the system and its
current perceived state is termed the discrepancy.
Her illustration for this, and the operation of the leverage points is a lake or
reservoir. This has stock, inflows and outflows:
(1)
The stock consists of the amount of water now in the lake.
(2)
Inflows consists of the volume of water entering the lake from a variety
of sources such as rivers, rainfall, drainage from nearby soils, and waste water
from a local industrial plant.
(3)
Outflows consists of the various amounts of water that leave the lake.
These might be water appropriated
for irrigation of crops, water taken for
industrial use, water to serve a camping site, natural evaporation, and overflow
water when the lake is full.
Assume now that there are three problems perceived with the lake. Water
levels are declining, pollution is increasing and hot water released into the lake
is harming fish and plant life in the lake. Thus there is a disecrepancy between
what the lake now is and what it needs to be.
Intervention in this system to correct these problems can occur with any of 12
leverage points. They are set out here by increasing order of effectiveness.
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