UML and Domain modelling (Week 2)

Question 1

What is UML?

Answer 1

It is a standardized graphical modelling language for communicating software design.

Question 2

What does UML allow?

Answer 2

Allows implementation-independent specification of:

• User/system interactions(required behaviours)
• Partitioning of responsibility(OO)
• Integration with larger or existing systems
• Data flow and dependency
• Operation orderings (algorithms)

Question 3

What are the motivations for UML?

Answer 3

This modelling language was created to

• help develop efficient, effective and correct designs, particularly object oriented designs.
• Communicate clearly with project stakeholders (developers,customers,etc)
• Give us the big picture view of the project

Question 4

Types of UML diagrams

Answer 4

Structure diagrams:

• Class diagrams
• profile diagrams
• component diagrams
• composite structure diagrams
• object diagrams
• deployment diagrams
• package diagrams

Behaviour diagrams (dynamic, changes to the system over time):

• Activity diagram
• Use case diagram
• State machine diagram
• interaction diagram
  
  • sequence diagram
  • communication diagram
  • interaction overview diagram
  • timing diagram

Question 5

What is a class diagram?

Answer 5

A central modelling technique that runs through nearly all object-oriented methods.
Describes the types of objects in the system and various kind of static relationships which exist between them
- Class diagram partitions the system into areas of responsibility (classes) and shows associations (dependencies) between them.
- Attributes (data), operations(methods), constraints, type-of (inheritance) relationships, access and cardinality (1 to many) may all be noted.

Question 6

What is a component diagram?

Answer 6

Component diagram shows dependencies between high-level system components

• The software in two distinct components/packages is separated; Components only interact through well-defined interfaces, there is no direct sharing of data or code
• Component is usually a collection of related classes, and will usually be specified by it’s own class diagram

Question 7

Why use a domain model?

Answer 7

It helps us to identify the relevant concepts and ideas of a domain. We decompose the domain into concepts or objects in the real world, it’s the basis for the design of the software.

Question 8

When is domain modelling done?

Answer 8

During object-oriented analysis

Question 9

What is the guideline for creating domain models?

Answer 9

Only create a domain model for the tasks at hand

Question 10

How to create a domain model?

Answer 10

1. Find conceptual classes:
   - reuse or modify an existing model
   - use a category list
   - identify noun phrases
2. Draw them as classes in a UML class diagram
3. Add associations and attributes