Lecture 3: Relationships and Packages

Question 1

What is a relationship?

Answer 1

A relationship is a connection between modelling elements

Question 2

What does association have between classes?

Answer 2

• Aggregation
• Composition
• Association classes

Question 3

What is a link?

Answer 3

• Is the connection between objects

* How they communicate using messages to invoke operations

Question 4

What is the term used to implement links in OO programming?

Answer 4

Object references/Pointers

Question 5

What is an association?

Answer 5

• Relationships between classes

* Links Instantiate association

Question 6

What is multiplicity?

Answer 6

Is a constraint that specifies the number of objects that can participate in a relationship

Question 7

What is a reflexive association?

Answer 7

• Is a relationship that “reflexes” itself.

* Objects of the class have links to other objects of the same class

Question 8

What is navigability?

Answer 8

• Traverse an object SOURCE CLASS into a TARGET CLASS

Question 9

What is the standard practice of navigability?

Answer 9

• Bi-directional associations have NO arrows
• Unidirectional associations have a SINGLE arrow
• Can’t show association that are navigable in BOTH directions

Question 10

When do we use association?

Answer 10

• The target class is important part of the model

* Target class shown in the model

Question 11

When do we use attributes?

Answer 11

• When it is not the important part of the domain (number/string)
• Just an implementation

Question 12

What is a association class syntax?

Answer 12

The association class consists of the class, the association and the dashed line

Question 13

What two important links does association class syntax consist of?

Answer 13

They are links that have attributes and operations

Question 14

When can you use association classes?

Answer 14

When there is only ONE UNIQUE LINK between objects

Question 15

What is generalisation?

Answer 15

A relationship between a common class that shares the same attributes and behaviour in a generalised class

Question 16

What is class inheritance

Answer 16

When a child class inherits all the features from the parent class

Question 17

What is overriding?

Answer 17

Subclasses override the methods of superclasses with the same signatures constraints and relationships

Question 18

What is an abstract class?

Answer 18

• A class that does not provide a complete declaration cannot be instantiated.

Question 19

What is Polymorphism?

Answer 19

• Has many forms of and changes of implementation.

* It allows you to design systems to use as an abstract class then substitute concrete classes

Question 20

What is analysis packages?

Answer 20

• Organises modelling elements into groups
o Defines the semantic boundary
o Provides parallel working and configuration

Question 21

What do analysis packages contain?

Answer 21

Classes, data. entities, use cases and analysis packages

Question 22

What is the UML term for analysis packages?

Answer 22

Logical grouping mechanism

Question 23

What is Package generalisation?

Answer 23

• More child packages inherit the public and private operations of the parent
• Child packages override the parent package

Question 24

What is Architectural Analysis?

Answer 24

Organises the groupings of model elements that have a strong semantic connection into cohesive packages

• Should be layered and partitioned
• Coupling packages should be minimised

Question 25

How do you find analysis packages?

Answer 25

• Discovered in model matures
• Natural groupings in use case model to identify the analysis packages
- One or more business process/actors

Question 26

What does the architectural analysis define?

Answer 26

The structure of the analysis model defines the logical system architecture