Non functional design and user interface

Design extends modeling from conceptual to what?

Concrete

What do analysis models evolve to

Design models

Design does what to analysis models

Add more layers

What should be added to an analysis model after it is finished?

System environment information

What do layers do?

Represent and seperate elements of the software architecture

Layer examples?

• foundation

• Problem domain

• Data management

• User interface

• Physical architecture

Package diagram

Is a UMl structure diagram that shows the structure of the designed system at the level of packages.

What do package diagrams do?

Allow users to see a different view of the system

What do packages group together?

Similar components

Balancing Functional & Structural Models: a class on a class diagram must be associated with at least one

Use case

Balancing Functional & Structural Models: what should an activity in an activity diagram and an even in a use case description be related to?

One or more operation on a class diagram

Balancing Functional & Structural Models: object node on an activity must be associated with

An instance or an attribute on a class diagram

Balancing Functional & Structural Models An attribute or an associated/aggregation relationship on a class diagram should be related to

The subject or object of a use case

Balancing Functional & Structural Models: Sequence and communication diagrams must be associated with

A use case

Balancing Functional & Structural Models: actors on a sequence and communication or CRUDE matrices must be associated with

Actors within a use case

Balancing Functional & Structural Models Messages on a sequence and communication diagram, transitions on

Behavioral state machines an entries in a CRUDE Matrix must relate to activities on an activity diagram and events in a use case

Balancing Functional & Structural Models: all complex objects in activity diagrams must be represented in a

Behavioral state machine

Guidelines for Balancing Structural & Behavioral Models: behavioral state machine must be associated with

Objects on a class diagram

Guidelines for Balancing Structural & Behavioral Models objects in sequence and communication diagrams must be associated with

Objects on a class diagram

Guidelines for Balancing Structural & Behavioral Models: Messages on sequence and communication diagrams and transitions on behavioral state machines must be associated with

operations in a class

Guidelines for Balancing Structural & Behavioral Models: States in a behavioral state machine must match

the different values of an attribute of an object

What are the characteristics of object oriented systems analysis and design?

• classes vs objects

• Encapsulation and information hiding

• Polymorphism and dynamic binding

• Inheritance

Close Coupling

Changes in one part of the design may require changes in another part

How to minimize interaction coupling

Restricting messages (LAW OF DEMETER)

Messages should only be sent by an

Object

Cohesive class

Object or method refers to a single thing

Method cohesion

• does a method perform more than one operation

• Performing more than one operation is more difficult to understand and implement

Class cohesion

• do the attribute and methods represent a single object

• Classes should not mix class roles domains or objects

Cohesion

Refers to what the class (or module) will do

Low cohesion

The class does a great variety of actions and is not focused on what it should do

High cohesion

The class is focued on what it should be doing (only methods relating to the intention of the class)

Methods for restructure and optimize the design

• review access paths between objects

• Review all attributes of each class

• Review direct and indirect

• Consider execution order of statements in often used methods

• Avoid recomputation by creating derived attributes and triggers

• Consider combining classes that form a one to one association

Non functional requirements that influence data management lauyer

• operational

• Performance

• Security

• Cultural and political

What are operational requirements affected by

Choice in hardware and operating system

What do performance requirements have issues with

Speed and capacity

Security requirements

Access controls encryption and backup

What can cultural and political requirements affect

Data storage

Architecture design is a combination of what?

Hardware and software

Where is hardware and software needed for a new application recorded

Specifications document

Software requirements

• operating system

• Special purpose of software

  • Include training needed maintenance warranties and licensing agreements

Hardware requirements

• use low level network diagram as a starting point

• Include type and quantity of servers peripherals storage and back up devices

• Describe minimum requirements

• Use an alternative matrix to evaluate vendor proposals

What non functional requirements are important in architecture design?

• operational

• Performance

• Security

• Cultural and political

• Legal implications

What is a good user experience

• the system is usable

• Tasks are completed more efficiently and with accuracy

• Mistakes are reduced

• Increases user satisfaction

• Ease of user adoption

What does interface design define

How the systems will interact with external entities

Graphics user interface (GUI)

Most common type of interfacce used today

Where does the problem domain and solution domain meet and interact

User interface (defining system boundary)

User interface is a communication exervis3e

• what is the message

• Who is the audience

• What is the best way to communicate the message to the audience

Guiding principles for UI design

• layout of screen form or report

• Content awareness

• Asthetics

• User experience

• Consistency

  • Minimal user effort

Content awareness

How well the user understands the information contained ( correct information)

Aesthetics

How well does it appeal to the user

Consistency

Refers to the similarity of presentation in different ares of the application

Ease of learning

• significant issue for inexperiences users

  • Relevant to systems with a large user population

Ease of use

• significant issue for expert users

• Most important in specialized systems

Ease of learning and use of use are related

• complementary: lead to similar design decisions

• Conflicting: designer must choose whether to satisfy novices or experts

Minim user effort

• interfaces should be designed to minimize the effort needed to accomplish tasks

• Three clicks rule

Thee clicks rule

Users should be able to go from main menu of a system to the information they want in no more than three mouse clicks

Path to successful user interface

1. Understand users

2. Organize the interface

3. Define standards

4. Develop prototype

What can you use to develop characterizations of various user groups

Personals

• interest

• Typical behaviors

• Goals and objectives

• Expectations

Understanding users

• users will have different goals and interntions

• Plan a UI that will be satisfying for that particular user group

Organize the interface

• define basic components an how they work together to provide functionality to users

  • Use Interface structure diagrams (ISD)

ISD

• shows how all screens forms and reports are related

• Shows how user moves from one to another

What is the goal of navigation design

To provide a clear and understandable user interface

Navigation design assumes

Users have not read the manual or attended training

What is the goal of input design

Simply and easily capture accurate data at the sources with minimal keystrokes

What are different ways to capture data

Widgets

What is the goal of output design

Convey what the user needs

Output design

• detail reports

• Summary reports

• Exception reports

• Turnaround documents

• Graphs

• Media for report can be electronic or hard copy

Suggestions for mobile design

• focus on needs not wants

• Remove fluff

• Utilize capabilities

• Make things vertically scrollable not horizontally

• Reduce interactions with the network to the extent possible

• Make use of reuseable patterns

• Designs for touchscreen

What impact do nonfunctional requirements have on UI design

• operational: hardware or software

• Performance: mobile computing and web browsing inject additional performance obstacjkes

• Security requirements:

• Political and cultural