1. Chapter 12 User Interface Design
Software Engineering: A Practitioner’s Approach, 6th edition
by Roger S. Pressman

2. Interface Design
Easy to learn?
Easy to use?
Easy to understand?

3. The user interface
System users often judge a system by its interface rather than its functionality
Poor user interface design is the reason why so many software systems are never used

4. Graphical user interfaces
Most users of business systems interact with these systems through graphical interfaces although.

5. GUI characteristics

6. Menu systems
Users make a selection from a list of possibilities presented to them by the system
The selection may be made by pointing and clicking with a mouse, using cursor keys or by typing the name of the selection
May make use of simple-to-use terminals such as touchscreens

7. Advantages of menu systems
Users need not remember command names as they are always presented with a list of valid commands
Typing effort is minimal
User errors are trapped by the interface
Context-dependent help can be provided. The user’s context is indicated by the current menu selection

8. Form-based interface

9. Command interfaces
User types commands to give instructions to the system e.g. UNIX
Easy to process using compiler techniques

10. Problems with command interfaces
Users have to learn and remember a command language. Command interfaces are therefore unsuitable for occasional users make errors in command. An error detection and recovery system is required

11. Golden Rules Place the user in control Reduce the user’s memory load
Make the interface consistent

12. User Interface Design Models
User model — a profile of all end users of the system
Design model — a design realization of the user model
Implementation model — the interface “look and feel” coupled with supporting information that describe interface syntax and semantics

13. Use case diagrams Terms and Concepts Common Properties Contents
A use case diagram is a diagram that shows a set of use cases and actors and their relationships.
Common Properties
A use case diagram is just a special kind of diagram and shares the same common properties as do all other diagrams.
Contents
Use case diagrams commonly contain
Use cases
Actors
Dependency,generalization,and association relationships.

14. Activity Diagrams
An activity diagram is essentially a flowchart, showing flow of control from activity to activity.
Common Use
Modeling a workflow
Modeling an operation.

15. Activity Diagram

16. Swimlanes