IS 460 Notes
Fundamentals of
General Systems Theory
by
Thomas Hilton
Why Study Systems
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Understanding
Influence
What is a System?
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Definition: A system is a set of
interacting components that operate
within a boundary to achieve some
purpose.
Postulate: Everything is a system.
Parts of a System
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Output
Input
Processes
Boundary
Environment
Input
Process C
Process B
Process A
Process E
Process D
Two Types Of Output
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Intended (purpose of the system)
Unintended (byproducts)
Control Issues? (Ashby’s Law)
Two Types of Input
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Main (transformed)
Maintenance (consumed)
Input
Three Types Of Processes
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Transformation
Process C
Interface
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Input
Output
Process B
Process A
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Control
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Output Sensor
Feedback Loop
Input Regulator
Process E
Process D
Boundary
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The boundary is where the system ends
and the environment begins.
Boundary identification is critical to your
professional survival
Boundary Identification is often
complicated by its intangible nature.
Environment
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The Environment is everything outside the
system.
The environment is infinite, so we commonly
discuss only the “relevant” environment.
The relevant environment is objects that
affect the behavior of the system but are
beyond its control.
Relationships
Between Systems
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Hierarchical
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Linear
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System
Super-system
Subsystem
All input comes from some system
All output goes to some system
“Closed” systems don’t exist.
Question…
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Is everything we know about a system?
Understanding Systems
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Identify the parts and their relationships.
Use the black box concept to concentrate on
inputs and outputs.
Use the closed system concept to concentrate
on processes (remember closed systems
don't really exist).
The Role of Observer
Perspective
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System definition depends on
perspective.
System behavior is affected by
observation.
System existence can depend on
observation.