Analysis Modeling
- The Analysis Model is the first technical representation of a system.
- Analysis Modeling uses a combination of text and diagrams to represent software requirements (data, function, and behavior) in an understandable way.
- Building analysis models helps make it easier to uncover requirement inconsistencies and omissions.
- Two types of analysis modeling are commonly used:
- Data Modeling uses Entity-Relationship Diagrams to define data objects, attributes, and relationships.
- Functional Modeling uses Data Flow Diagrams (DFD) to show how data are transformed inside the system.
- Behavioral Modeling uses State Transition Diagrams to show the impact of events.
- Analysis work products must be reviewed for completeness, correctness, and consistency.
Work Products of Analysis Modeling:
- Data object descriptions
- Entity relationship diagrams
- Data flow diagrams
- State transition diagrams
- Process specification and
- Control specifications
Analysis Model Elements:
Data dictionary
- Lies at the core of the model.
- It is a repository that contains the descriptions of all data objects consumed or produced by the software.
Three different diagrams surround the core.
(1) Entity relationship diagram (ERD):
- Depicts relationships between data objects
(2) Data flow diagram (DFD):
- Serves two purposes:
- To provide an indication of how data are transformed as they move through the system;
- To depict the functions (and sub-functions) that transform the data flow (a function is represented in a DFD using a process specification or PSPEC)
(3) State transition diagram (STD):
- Indicates how the system behaves as a consequence of external events, states are used to represent behavior modes. Arcs are labeled with the events triggering the transitions from one state to another (control information is contained in control specification or CSPEC)
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