This document discusses object relationships in class diagrams. It describes three main types of relationships: association, generalization (super-sub structure), and aggregation. Association represents connections between classes and can be binary, ternary, or higher order. Identifying associations involves analyzing class interactions and dependencies. Common association patterns include location and communication. The document provides guidelines for eliminating unnecessary associations to simplify diagrams.

1. Identifying object
relationships ,attributes ,
methods,

2. Types of relationships
• Association
• Super-sub structure (generalization
hierarchy)
• Aggregation and part of a structure

3. Association
• Represents physical or conceptual
connection between 2 or more objects
• Binary association
– Line connecting 2 classes
• Ternary and higher order association
– Diamond connecting to a class symbol by line
• Association name is written above or
below the name
• Includes name of the role

4. Cont..
• Identifying association
• Common association pattern
• Eliminating unnecessary association

5. Identifying association
• Begins by analyzing the interaction among
classes
• Ask following questions
– Is the class capable of fulfilling the required task by
itself
– If not, what does it need
– From what other class can it acquire what it needs
• Guideline
– Dependency between 2 or more classes
• Association corresponds to verb or prepositional phrase
– Reference from one class to another
• Implicit or taken from knowledge

6. Common association pattern
• Location association
– Ex: next to, part of , contained in
• Communication association
– Ex :talk to, order to
operator
customer
order

7. Eliminate unnecessary association
• Implementation association
– Defer implementation specific association to design phase
– Not concerned about relationship among business objects
• Ternary association
– Complicate the representation
– Req
• Restate ternary association to binary association
• Directed actions or derived association
– Can be defined in terms of other association
– Leads to redundancy
– Ex:
Grant parent of
raman abi
parent of parent of
raman murugan abi

8. Super-sub class relationships
• Generalization hierarchy
• Represents the inheritance re