 |
system notions
|
|
The basic notions are covered in the Foundations
of Business course offered by Veryard Projects
and Antelope Projects. Advanced
notions are covered in our Organizational Behaviour
course.
Basic Notions
Feedback, Feedforward
Feedback and feedforward are information flows between systems or subsystems
that have a causal impact.
Feedback refers to an information flow that sets up a causal loop. Feedback
may be positive or negative. Positive feedback has the effect of amplifying
the original stimulus, while negative feedback has the effect of reducing
or reversing the original stimulus.
In the absence of other controls or influencing factors, positive feedback
tends to result in explosive growth, while negative feedback tends to result
in either equilibrium or oscillation.
Under certain conditions, negative feedback can be used to maintain
system properties - see homeostasis.
Goal-directed
"The most distinctive characteristic of the behaviour of higher organisms
is its goal-directedness, its apparent purposiveness. In fact, it is largely
through this apparently teleological nature of their activities that living
organisms betray their exceptional organization. ... The movements of a
chick pecking at a grain, a rabbit digging its burrow, a pike chasing its
prey, a bee homing on its hive, are the sort of examples one could quote
of activities that could be paralleled to a significant extent by known
forms of automatic controls as used in industry, aircraft, guided missiles,
etc." [Gerd Sommerhoff, 1969]
Homeostasis
Example: A heating system switches itself on when the temperature
falls below the desired temperature, and switches itself off when the temperature
rises above the desired temperature. This control mechanism aims to maintain
the temperature approximately equal to the desired temperature.
SocioTechnical
A description of something (usually a system) that identifies both socially
mediated relationships and technically mediated relationships.
Many people think of a socio-technical system as a composite system,
containing some social subsystems and some technical subsystems. This is
a simplification, which can sometimes be dangerously misleading.
All social systems are technically mediated. We get an increasing amount
of our information about our social world through technical media: email,
telephone, management information systems, television, Reuters newswire.
These technologies screen information for us, screen information
from us.
(For example, computers and televisions both provide information as
services through a screen. The screen is both literal and metaphorical.
It is a surface on which the data are presented, and also a filter that
controls what the user sees. The screen is a two-sided device -- it both
reveals
information
and hides information.)
And all technical systems are socially mediated. Technology is produced,
distributed and managed by people within social structures, for socio-economic
or political purposes. It is interpreted and used according to social intentions.
For some purposes, therefore, it is appropriate to treat all the subsystems,
even the smallest components, of a socio-technical system as if they were
themselves socio-technical.
System (Closed, Open)
| Closed System Thinking |
Regarding a system (such as an organization or enterprise) as independent
and autonomous. This means that problems may be largely analysed with reference
to internal structure and process, and without reference to the external
environment. |
| Open System Thinking |
Regarding a system as interdependent with its environment, with exchanges
of material, information and energy. |
Advanced Notions
Autopoiesis
This notion was introduced by the biologists Humberto Maturana and Franscisco
Varela. It refers to autonomous systems that are self-creating, self-organizing
and self-preserving. It is commonly applied to biological organisms, and
also to human organizations.
Emergence
(The appearance of) properties of a whole system that are not located in
its parts. With engineered systems, these properties don’t manifest themselves
until the whole system is assembled and commissioned. With evolved systems,
these properties often disappear when the system is taken apart.
Hysteresis
Imperfect or delayed return to a previous state (memory effect). Delayed
response to a stimulus (cause-effect lag).
Requisite Variety
A principle first formulated by W.R. Ashby, which states that a control
mechanism must have access to the same degree of diversity as the system
it is attempting to control. In open systems thinking, this implies that
the internal regulatory mechanisms of a system must be at least as diverse
as its environment.
Viable Systems Model (VSM)
A framework model of complex systems, developed by Stafford Beer.
