UML

Question 1

Define: Use Case

Answer 1

A list of event steps defining the interactions between an actor and a system
Ultimate criterion: if it ends with a value for the user, it is a use case

Question 2

Define: Essential use case

Answer 2

Describes user intentions and system responsibilities

Question 3

Define: System use case

Answer 3

Describes user actions and system responses at a technical level

Question 4

What are the 3 UML use case relationships

Answer 4

Includes:
a common subpart is used within a containing use case
Extends:
A variant or exceptional situation that extends the normal case
Generalisation:
Several special use cases generalised to a common general description

Question 5

Capturing alternative execution paths in a communication diagram

Answer 5

with guards and letter notation

Question 6

Using interaction diagrams in implementation phase

Answer 6

Creating method skeletons

Question 7

Using interaction diagrams in the testing phase

Answer 7

Generate test cases

Question 8

Value of super states

Answer 8

Reduce complexity of system by hiding state information

Question 9

Define: Super-state

Answer 9

The parent state of one or multiple substates

Question 10

Define: OCL

Answer 10

Derivative of UML describing rules for UML models

Question 11

Uses of OCL

Answer 11

Provide constraints on:

Limits, Uniqueness, Consistency and Contracts

Question 12

OCL Limits

Answer 12

Constrain values to certain ranges

Question 13

OCL Uniqueness

Answer 13

Constrain instance values to be unique

Question 14

OCL Consistency

Answer 14

Express invariants on data structures

Question 15

OCL contracts

Answer 15

Pre/post conditions for operations

Question 16

OCL invariants

Answer 16

constraint that states a condition that must always be met by all instances of the component, type or interface. Invariants must be true all the time

Question 17

When to use OCL

Answer 17

To express restrictions that can’t be shown with visual notation only

Question 18

How do substates reduce complexity of state diagram

Answer 18

Allows for single superstate with multiple substate variations I.e. concurrent substates,

Question 19

Situation for textual constraints in a diagram (2)

Answer 19

1. textual constraints are easier to read than standard logical notations
2. “loose semantics” allows admissible solutions to the constraint, without prescribing a specific solution

Question 20

Properties of a good class diagram

Answer 20

Honestly, not sure

Simple? Let me know what you think, Raz (If you see this)

Question 21

Why are class diagrams created at the analysis stage of engineering

Answer 21

Helps understand the requirements of the domain and identify its components

Question 22

Sequence diagram vs Communication diagram

Answer 22

Sequence diagram shows how interactions progress with respect to time
Communication diagram only shows in what order interactions progress

Question 23

UMLs approach to container types (I.e. Set)

Answer 23

On the association line, example:

Book: 1 {readOnly} has -> {ordered, unique} * :Reservation

Question 24

Benefits of association classes/high arity association

Answer 24

No multiple relationships between two objects

High arity associations (aggregation in between) give a symmetric contribution to relationship

Question 25

UML language/notation features to deal with complexity (3)

Answer 25

Superstates - reduce complexity by information hiding
Textual constraints?
Not sure, again

Question 26

Qualified Association

Answer 26

Kind of like an enum, I guess. Ex. Car has wheels, wheels have positions between them and cars