-
Define "Logical Model"
Shows what the system must do, regardless of how the system will be constructed.
-
Define "Physical Model"
Describes how the system will be constructed.
-
Define "Data Flow Diagram (DFD)"
Uses various symbols to show how the system transforms input data into useful infomation.
-
Define "Process"
Recieves input data and produces output that has a different content, form, or both.
-
Define "Business Logic/Business Rules"
Transforms the data and produces the required result.
-
Define "Black Box"
A process symbol
-
Define "Data Flow"
A path for data to move from one part of the information system to another.
-
Define "Spontaeous Generation" and would you use it?
Process that produces output, but has no input data flow.
No.
-
Define "Black Hole" and would you use it?
Process that has input, but produces no output.
No.
-
Define "Gray Hole" and would you use it?
Process that has at least one input and output, but the input is obviously insufficient to generate a coherent output.
- Example:
- Data of Birth ------> [CALCULATE GRADE]------->Final Grade
No.
-
Define "Data Store"
Used by the DFD to represent data that the system stores because one or more processes must access it a later time.
-
What must a Data Store be connected to?
Process.
-
Define "Entity", how is the symbol represented
A person, place, thing, or event for which data is collected and maintained.
A rectangle with shading to make it look 3 dimensional.
-
Define "Terminators" and what are they usually called?
Terminators are data origins or final destinations.
They are also known as "DFD Entities".
|
|
