Chp5 Interface Design

CHAPTER CHAPTER 55OUTPUT AND OUTPUT AND

USER USER INTERFACE INTERFACE

DESIGNDESIGN

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PHASE DESCRIPTION Systems Design is the third of five phases in

the systems development life cycle (SDLC) Now you are ready to begin the physical

design of the system that will meet the specifications described in the system requirements document

Systems design tasks include output and user interface design, data design, and system architecture

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CHAPTER OBJECTIVES Discuss output design issues and various

types of output Design various types of reports, and suggest

output controls and security Explain the concept of user interface design

and human-computer interaction, including the basic principles of user-centered design

List specific guidelines for user interface design

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CHAPTER OBJECTIVES Describe user interface techniques, including

screen elements and controls Explain input design concepts, techniques,

and methods Describe guidelines for data entry screen

design Use validation checks for reducing input

errors Design effective source documents and input

controls

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INTRODUCTION Output and user interface design is the first task

in the systems design phase of the SDLC Output design focuses on user needs for screen

and printed forms of output, while user interface design stresses user interaction with the computer, including input design and procedures

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OUTPUT DESIGN Before designing output, ask yourself several questions:

What is the purpose of the output? Who wants the information, why it is it needed, and how

will it be used? What specific information will be included? Will the output be printed, viewed on-screen, or both?

What type of device will the output go to? To complete your understanding, you should meet with the

users to find out exactly what kind of output is needed Your answers will affect your output design strategies

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TYPES OF OUTPUT Although most output are screen display and printed

matter, technology is having enormous impact on how people commun and obtain information

Output can take many forms Here are various output types & technology available

Internet-based information delivery E-mail Audio – audio output Automated facsimile systems

Faxback systems Computer output microfilm (COM)

Microfilm, microfiche Computer output to laser disk (COLD)

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SPECIALIZED FORMS OF OUTPUT An incredibly diverse marketplace requires a variety

of specialized output Output from one system often becomes input into

another system Eg production data from manufacturing system becomes

input to the inventory system Although digital technology has opened new

horizons in business communications, printed output still is a common type of output, and specific considerations apply to it

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PRINTED AND SCREEN OUTPUT Although many organizations strive to reduce the

flow of paper and printed reports, few firms have been able to eliminate printed output totally

Because they are portable, printed reports are convenient, and even necessary in some situations

Printed output also is used as Turnaround documents, which are output document that are later entered back into the same or another IS Eg telephone bill might be turnaround document printed

by the company’s billing system. When you return the required portion of the bill with your check, the bill is scanned into the company’s account receivable system to record the payment

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REPORTS Whether printed or viewed-on screen, report should be

attractive and easy to understand To be useful, report must include info that user need

Detail reports Produce one or more lines of output for each record processes Detail line Control field Control break Control break report Can be quite lengthy Better alternative is to produce an exception report

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REPORTS Exception reports

Display only those record that meet a specific condition

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REPORTS Summary reports

Report used by individuals at higher levels in the organization include less details than reports used by lower level employees

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USER INVOLVEMENT IN REPORT DESIGN

Printed reports are an important way of delivering information to users, so recipients should approve all report designs in advance

To avoid problems submit each design for approval as you complete it, rather than waiting until you finish all report designs

When design a report, prepare a sample report called Mock-up or prototype for user to review

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REPORT DESIGN PRINCIPLES Printed reports must be attractive, professional,

and easy to read Report headers and footers Page headers and footers Column heading alignment Column spacing

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REPORT DESIGN PRINCIPLES Field order

Fields should be displayed and grouped in a logical order

Grouping detail lines It is meaningful to arrange detail lines in groups Group header Group footer

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REPORT DESIGN ISSUES Too much detail is on the page, forcing users to

search for the information they need Good design standards produce reports that are

uniform and consistent When a system produces multiple reports, each

report should share common design elements After a report design is approved, you should

document the design in a report analysis form

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DESIGNING CHARACTER-BASED REPORTS Although majority report designed in graphical

environment, many system still produce one or more character-based reports

That use a character set with fixed spacing When report designer create or modify a

character-based report, they use a traditional tool that still work, called printer spacing chart

It is a grid of rows and column where u indicate print position and field sizes

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OUTPUT CONTROL AND SECURITY Output must be accurate, complete, current, and

secure Company uses various output control method to

maintain integrity and security Output security – protect privacy rights and shield

organization’s property data from theft or unauthorize acc

The IT department is responsible for output control and security measures

Many companies have installed diskless workstations

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A diskless workstation support a full-featured user interface,But can limit the printing or copying of data

USER INTERFACE DESIGN

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USER INTERFACE DESIGN Although output design involves a separate set of

physical design issues, it is an integral part of a larger concept called a user interface (UI)

A UI describe how users interact with a computer system and consists of all the hardware, software, screens, menus, functions, and features that affect two-way communications between the user and the computer

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EVOLUTION OF THE USER INTERFACE Often, UI mainly consist of Process-control

screen that allow user to send command to system

As information management evolved from centralized data processing to dynamic, enterprise-wide systems, the primary focus also shifted — from the IT department to the users themselves

In a User-centered system, the distinction blurs between input, output and interface itself

UI requires an understanding of human-computer interaction and user-centered design principles

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HUMAN-COMPUTER INTERACTION A UI is based on basic principles of Human-

computer interaction (HCI) HCI describe the relationship between computers

and people who use them to perform business related tasks

Industry leaders Microsoft and IBM both devote considerable resources to user interface research

As system analyst, you’ll design UI to create a user-friendly design that is easy to learn and use

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HUMAN-COMPUTER INTERACTION History and evolution of HCI begin with user typing

complex command, through the introduction of the Graphical user interface (GUI)

Dr. Clare-Marie Karat states that “in this new computer age, the customer is not only right, the customer has rights.”

The user rights cited by Dr. Karat include Perspective – user is always right Installation – user has right to install and uninstall sw

and hw Compliance – user has right to system that perform

exactly as promised Instruction – user has right to easy –to-use instruction Control – user has right to control system and get

respond

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HUMAN-COMPUTER INTERACTION The user rights cited by Dr. Karat include

Feedback – user has right to system to provide clear, accurate info

Dependencies Scope Assistance Usability – user should be master of sw and hw

tech not vice versa

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BASIC PRINCIPLES OF USER-CENTERED DESIGN Although IT profess have different views about

interface design, most agree that good design depends on 8 basic principle:- Understand the underlying business functions Maximize graphical effectiveness Profile the system’s users Think like a user Use prototyping

StoryboardUsability metrics

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BASIC PRINCIPLES OF USER-CENTERED DESIGN Basic Principles of User-

Centered Design Design a comprehensive

interface Continue the feedback process Document the interface design

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GUIDELINES FOR USER INTERFACE DESIGN

It is important to design a UI that is easy to use, attractive and efficient

Follow eight basic guidelines1. Focus on basic objectives2. Build an interface that is easy to learn and

use3. Provide features that promote efficiency4. Make it easy for users to obtain help or

correct errors5. Minimize input data problems

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GUIDELINES FOR USER INTERFACE DESIGN

Follow eight basic guidelines6. Provide feedback to users7. Create an attractive layout and design8. Use familiar terms and images

Good user interface design is based on a combination of ergonomics, aesthetics, and interface technology

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USER INTERFACE CONTROLS The designer can include many control features

such as Menu bar Toolbar Command button Dialog box Text box Toggle button

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USER INTERFACE CONTROLS User Interface Controls

List box – scroll bar Drop-down list box Option button, or radio button Check box Calendar control Switchboard

INPUT DESIGN

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INPUT DESIGN Input technology has changed dramatically in recent

years No matter how data enters an IS, the quality of the

output is only as good as the quality of the input The concept known as Garbage in, garbage out (GIGO) During input design, determine how data will be

captured and entered into system Data capture – uses automated or manually operated

devices to identify source data and convert to compute readable form eg bar code readers

Data entry – is the process of manually entering data into IS, in a form of keystrokes or mouse clicks

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INPUT AND DATA ENTRY METHODS Input process should be efficient, timely and logical First decision is whether to use batch or online input

methods Each method has adv and disadvtg

Batch input Data entry performed on a specified time schedule eg

daily, weekly, or longer Eg payroll dept collect time cards and enter data as

batch Online input

Online data entry – use on business activity Source data automation – combine online data entry

and automated data capture using input devices eg RFID tags or magnetic data strips. Eg use at POS, ATMs

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Tradeoffs Even online input offers many advtg, it does have

some disadvtg Eg unless source data automation is used,

manual data entry is slower and more expensive than batch input because it is performed at the time the transaction occurs and often done when computer demand is at its highest

The decision to use batch or online input depends on business requirements

Eg hotel reservation must be entered and process immediately, but hotel can enter their monthly performance figures in batch. In fact some input occurs in batches

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INPUT VOLUME To reduce input volume, you must reduce

number of data items required for each transaction

Guidelines will help reduce input volume1. Input necessary data only2. Do not input data that the user can

retrieve from system files or calculate from other data

3. Do not input constant data4. Use codes

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DESIGNING DATA ENTRY SCREENS Some user work with many features of UI and

some spend time entering data Here discussed interface guideline and concept

that primarily relate to repetitive data entry Most effective method of online data entry is

form filling Guidelines will help you design data entry screens

1. Restrict user access to screen locations where data is entered

2. Provide a descriptive caption for ever field, and show the user where to enter the data and the required or maximum field size

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DESIGNING DATA ENTRY SCREENS Guidelines will help you design data entry

screens3. Display a sample format if a user must

enter values in a field in a specific format4. Require an ending keystroke for every field5. Do not require users to type leading

zeroes for numeric fields6. Do not require users to type trailing zeroes

for numbers that include decimals

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DESIGNING DATA ENTRY SCREENS Guidelines will help you design data entry screens

7. Display default values so operators can press the ENTER key to accept the suggested value

8. Use a default value when a field value will be constant for successive records or throughout the data entry session

9. Display a list of acceptable values for fields, and provide meaningful error messages

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screens10. Provide a way to leave the data entry

screen at any time without entering the current record

11. Provide users with an opportunity to confirm the accuracy of input data before entering it

12. Provide a means for users to move among fields on the form

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screens13. Design the screen form layout to match

the layout of the source document14. Allow users to add, change, delete, and

view records15. Provide a method to allow users to search

for specific information

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INPUT ERRORS Reducing the number of input errors improves

data quality So, identify and correct errors before they enter

the system by using data validation check A data validation check improves input quality

by testing the data and rejecting any entry that fails to meet specified conditions

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INPUT ERRORS You can design at least eight types of data

validation checks into the input process1. Sequence check2. Existence check3. Data type check4. Range check – limit check5. Reasonableness check6. Validity check – referential integrity7. Combination check8. Batch controls – hash totals

Read detail pg 317

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INPUT CONTROL Input control include necessary measures

to ensure that input data is correct, complete and secure

Focus on input control during every phase of input design

Every piece of information should be traceable back to the input data that produced it

Provide an audit trail – that record the source of each data item and when it entered the system

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INPUT CONTROL Data security – protect data from loss or

damage Company must have a Records retention

policy that meets all legal req and business needs

Sensitive data must be encrypted in a process called encryption , so only users with decoding sw can read it

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CHAPTER SUMMARY The chapter began with a discussion of output

design issues and a description of various types of output

User-centered design principles require an analyst to understand the business functions, maximize graphical effectiveness, profile the system’s users, think like a user, use prototyping, design a comprehensive interface, continue the feedback process, and document the interface design

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CHAPTER SUMMARY An effective way to reduce input errors is to

reduce input volume You can also reduce errors by using well-

designed data entry screens and by using data validation checks

Chapter 5 Complete

Chp5 Interface Design

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