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Unit 9: System Engineering
Behavioral Models Notes
Behavioral models are used to describe the overall behaviour of a system
Two types of behavioral model are shown here
Data processing models that show how data is processed as it moves through the system
State machine models that show the systems response to events
Did u know? Explain the requirement of these models.
Both of these models are required for a description of the system’s behavior.
Data-processing Models
Data flow diagrams are used to model the system’s data processing
These show the processing steps as data flows through a system
Intrinsic part of many analysis methods
Simple and intuitive notation that customers can understand
Show end-to-end processing of data
Order Processing DFD
Figure 9.4: Order Processing DFD
Data Flow Diagrams
DFDs model the system from a functional perspective
Tracking and documenting how the data associated with a process is helpful to develop an
overall understanding of the system
Data flow diagrams may also be used in showing the data exchange between a system and other
systems in its environment
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