Page 159 - DCAP405_SOFTWARE_ENGINEERING

Software Engineering

Notes 2. Attributes are characteristics of the elements that may be perceived and measured. For
example: quantity, size, color, volume, temperature, and mass.
3. Relationships are the associations that occur between elements and attributes. These
associations are based on cause and effect.

Notes We can define the state of the system by determining the value of its properties (the
elements, attributes, and/or relationships).

Types of Systems

Scientists have examined and classified many types of systems. Some of the classified types
include:
1. Isolated System: It is a system that has no interactions beyond its boundary layer. Many
controlled laboratory experiments are this type of system.
2. Closed System: It is a system that transfers energy, but not matter, across its boundary to
the surrounding environment. Our planet is often viewed as a closed system.
3. Open System: It is a system that transfers both matter and energy can cross its boundary to
the surrounding environment. Most ecosystems are example of open systems.

4. Morphological System: This is a system where we understand the relationships between
elements and their attributes in a vague sense based only on measured features or
correlations. In other words, we understand the form or morphology a system has based
on the connections between its elements. We do not understand exactly how the processes
work to transfer energy and/or matter through the connections between the elements.
5. Cascading System: This is a system where we are primarily interested in the flow of
energy and/or matter from one element to another and understand the processes that
cause this movement. In a cascading system, we do not fully understand quantitative
relationships that exist between elements related to the transfer of energy and/or matter.
6. Process-response System: This is a system that integrates the characteristics of both
morphological and cascading systems. In a process-response system, we can model the
processes involved in the movement, storage, and transformation of energy and/or matter
between system elements and we fully understand how the form of the system in terms of
measured features and correlations.

7. Control System: A system that can be intelligently manipulated by the action of humans.
8. Ecosystem: It is a system that models relationships and interactions between the various
biotic and abiotic components making up a community or organisms and their surrounding
physical environment.
There are four basic types of system depending on whether the parts and the whole can display
choice, and therefore, be purposeful. The four kinds of system are shown in Table 9.1

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