Tom Kelliher, CS 319
Oct. 30, 1998
- Requirements analysis.
- Models are abstractions, hopefully maintaining the salient features
of a system.
- Models vs. representations. (Abstracts vs. translations.)
- Show how data flows through a sequence of processing steps.
- The model most accessible to non-technical staff?
- Elements of a dataflow diagram:
- Develop a dataflow diagram of an ATM transaction.
- Show the logical relationship of data within a system.
- Entity: basically, a record.
- Relation: The relationship between different (types of) entities.
- Elements of an ER diagram:
- What data is necessary in processing an ATM transaction? Develop an
ER diagram for that data.
- Object class: an abstraction over a set of objects which identifies
common attributes and operations or services.
- Often a foreign concept to end-users.
- Elements of a class hierarchy diagram:
- Develop class hierarchy and object aggregation diagrams for
sub-systems within an ATM system.
Thomas P. Kelliher
Fri Oct 30 10:47:34 EST 1998