College of Education

School of Continuing and Distance Education2017

INFS 328

Systems Analysis and Design

Session 6 – System Design – Part 1

Lecturer: Prof. Ellis Edwin Badu, Dept. of Information Studies Contact Information: eebadu@ug.edu.gh

Session Overview

In the Analysis phase, you studied how to analyse a currentinformation system by coming up with a logical model of thenew system and other development strategies.

With this phase you will learn about physical design of aninformation system that will meet the specificationsdescribed in the system requirements document.

System design tasks include output and user interfacedesign and data design.

Slide 2

Session Outline

The key topics to be covered in the session are as follows:

• Output Design

• User Interface Design

• Input Design

• Data Design

Slide 3

OUTPUT DESIGNTopic One

Slide 4

System Design – Output Design

Output DesignAs a system analyst, you will have to design the screen for your usersand other output printed forms. The following are the essentialelements of the output design.1. Purpose of the output.2. Audience of the information and why the information is needed

and how the information will be used.3. Specific information needed.4. Form of output either printed, screen view or both or the type of

device the output will go to.5. When the information will be provided and update frequency6. Security and confidentiality.

.

Slide 5

System Design – Output Design

Types of outputThe type of output needed and the technologyneeded usually are decided during the analysisphase based on user requirements. In thedesign phase, actual reports, screen forms andother delivery methods are designed. Some ofthe other delivery methods are: Internet, E-mail, Audio output, automated facsimilesystems, computer output microfilm, computeroutput to laser disk..

Slide 6

System Design – Output Design

Types of output• Internet-based information delivery. Some organisations use the

internet to reach new customers and markets so web designersmust provide user-friendly screen interfaces that display outputand accept input from customers. For example, a system providescustomised responses to product inquiry or requests technicalsupport, the system responds with appropriate information froman on-site knowledge base.

• E-mail – This is an essential means of internal and externalbusiness communication. E-mail has virtually replaced traditionalmemos and printed correspondence. Companies send new productinformation to customers via e-mail and financial servicescompanies use e-mail messages to confirm on-line stock trades.

Slide 7

System Design – Output Design

Types of output• Audio Output – This can be attached to an e-mail message or

inserted as an audio clip in a Microsoft word document. Inaddition, many organisations use automated systems to handlevoice transactions and provide information to customers. For,example, by using a telephone keypad, a customer can confirm anairline seat assignment, check a credit card balance or determinethe current price of a commodity.

• Automated Facsimile System – Some companies use automatedfacsimile, sometimes called faxback systems to allow a customer torequest a fax using e-mail via the company’s website or bytelephone. The response is transmitted in a matter of seconds backto the user’s fax machine.

Slide 8

System Design – Output Design

Types of output• Computer Output Microfilm (COM) – Examples of these are

Microfilm and Microfiche. These capture an image of a document and produce film output. Users then retrieve, view and print the images. Microfilm records the images on a roll of film, and microfiche records images using a small sheet of film.

• Computer output to laser disk (COLD) – This is another way to store images of paper documents. Using COLD technology a paper document is scanned and the digital image is stored on a high density laser disk medium. COLD technology also enables rapid information retrieval of formatted information.

Slide 9

System Design – Output Design

Other Specialised Forms of Output – There are otherspecialised forms of output. Some of them are briefly describedbelow:• retail point–of –sale terminals to handle computer based

credit card transactions, print receipts and update inventoryrecords

• automatic teller machines• special purpose printers that produce labels, photos driving

licenses and even lottery tickets• plotters that produce high quality images such as blue prints

maps• digitised photos that companies can print on employee

identification cards

Slide 10

System Design – Output Design

Printed and Screen OutputReports can be printed outputs or screen outputs. Whetherprinted or viewed on screen, reports should be attractive and easyto understand. Managers and users judge an entire project by thequality of the reports. Reports can be classified into: Detail reports,Exception reports and Summary reports. The users of aninformation system must approve all report designs in advance asthe information is delivered to them. In designing a report, asample report called Mock-up or prototype is normally preparedfor review by users. Reports can be created using word processor,report generator or a printer spacing chart.

The principles for report design include report headers andfooters, page headers and footers, column headings andalignment, column spacing, field order and grouping of detail lines.

Slide 11

Questions

Individual Assignment:

List eight delivery outputs.

Forum Question

Explain the difference between printed and screen output

Slide 12

USER INTERFACE DESIGNTopic Two

Slide 13

User Interface Design

Guidelines for User Interface Design

A good user interface design is based on ergonomics,aesthetics and interface technology. Ergonomics describeshow people work, learn and interact with computers.Aesthetics focuses on how an interface can be madeattractive and easy to use. Interface technology provides theoperational structure required to carry out the designobjectives.

Every interface should therefore be designed to make it easyto use, be attractive and efficient and must be guided by thefollowing points.

Slide 14

User Interface Design

User Interface Design Guides

• Focus on basic objectives. Facilitate the system designobjectives rather than calling attention to the interface

• Build an interface that is easy to learn and use.

• Promote features that promote efficiency by organisingtasks commands and functions in groups that resembleactual business operation.

• Make it easy for users to obtain HELP or correct errors.Ensure that HELP is always available. HELP screens shouldprovide information about menu choices, procedures,shortcuts and errors.

Slide 15

User Interface Design

User Interface Design Guides

• Minimise input problems by providing messages, forexample, an ID number not found.

• Create an attractive layout and design by usingappropriate columns to highlight different areas of thescreen, avoid gaudy and bright columns.

• Use familiar terms and images. For example, file, exit,help. Use familiar commands such as cut, copy and printetc.

Slide 16

Questions

Individual Assignment:

Design a printed output for a student registration system.The output should include statement name, name ofresidence, course, department and name of faculty. Let theheading be student registration system.

Forum Question

What do you understand by user interface?

Slide 17

INPUT DESIGNTopic Three

Slide 18

Input Design

Input DesignAfter designing the output, the input should also bedesigned as a second part of the interface. Input technologyhas changed dramatically. Businesses use the newtechnology to speed up the input process, reduce costs andcaptured data in new forms such as digital signature.

A good input design ensures quality, accuracy andtimeliness. Input design is about how data will be capturedand entered into the information system.

Slide 19

Input Design

Input DesignData capture uses an automated or manually operateddevice to identify source data and convert it into computer– readable form. Examples of data capture devices includecredit card scanners and bar code readers.

Data entry is the process of manually entering data into theinformation system, usually in the form of key strokes ormouse clicks. Every input design must have the followingobjectives.

Slide 20

Input Design

Six Main Objectives of Input Design

• Select a suitable input and data entry method. Anexample is batch input (entry on a specified timeschedule) or online input such as source dataautomation.

• Reduce input volume. (Reduce the number of data itemsrequired for each transaction in order to reduce volume).This avoids unnecessary labour cost as data capture ordata entry require time and effort.

• Design attractive data entry screen.Slide 21

Input Design

Six Main Objectives of Input Design• Use validation checks to reduce input errors. Reducing errors

improves data quality.

• Design required source documents. A source document is a formused to request and collect input data, trigger or authorise aninput action, and provide a record of the original transaction.During the input design stage, you develop source documents thatare easy to complete and inexpensive.

• Develop effective input controls. Input control includes thenecessary measures to ensure that input data is correct, completeand secure. There are some common types of input devices youshould be familiar with.

Slide 22

Input Design

Common Types of Input Devices

The following are some input devices:

• Biological feedback device –this creates digital image ofbiological data such as finger prints, retina patterns etc.

• Digital collection device –this is a fixed or portabledevice that can read data on site, like ATM.

• Digital camera.

• Electronic whiteboard – this is an electronic version oftraditional white board that can capture and store text orgraphics written or drawn on the board.

Slide 23

Input Design

Common Types of Input Devices

The following are some input devices:

• Graphic input devices –include light pens, digitisers andgraphics tablets that allow drawings to be translated intodigital form.

• Hand held computer stylus – device that allows users toform characters on the screen of a hand held computer.

• Input devices for physically challenged

• Internet workstation – enables user to provide input toweb-based intranet or internet recipients

• Key board -Slide 24

Input Design

Common Types of Input Devices

The following are some input devices:

• MICR (magnetic ink-character recognition) technology usedto read magnetic ink

• Mouse – pointing device that allows the user to move theinsertion point to a specific location on a computer screen

• Micro phone – a microphone converts sound waves intodigital information

• Scanner – device that reads printed bar codes, characters orimages

• Terminal – device such as screen on monitor

Slide 25

Input Design

Common Types of Input Devices• Video input – video camera input, in digital form that can be

stored and played later• Touch screen – sensors that allow users to interface with the

computer and select options by touching specific locations on thescreen

• Voice input device – device that allows users to enter data andissue commands using spoken words

• Wireless input – wireless input devices are wireless versions oftraditional scanners, barcode readers and data collection devices

• Radio Frequency Identification (RFID) –this is a technology used totrack down items in a wide range of information systems includinginventory control, point- of-sale and monitor peoples movement insecurity management system

Slide 26

Questions

Individual Assignment:

List ten common types of inputs.

Forum Question

Discuss five input devices and their uses

Slide 27

DATA DESIGN

Topic Four

Slide 28

Data Design

Introduction

Data Design touches on the physical design plan for dataorganisation, storage and retrieval. It is exactly the same asdata base management course you studied in the firstsemester of level 300. Because of this, the section will provideonly a summary of what you have already studied in level 300.

Summary of Data DesignBefore constructing an information system, you mustunderstand basic data design concepts, including datastructures and the characteristics of file processing anddatabase systems including Web-based database design. Thefollowing is a summary of the essential facts you should know.

Slide 29

Data Design

Files and tables

These usually contain data about people, places, things orevents that affect the information system. File processingsystems also file-oriented systems, manage data stored inseparate files including master files, table files, transaction files,work files, security files and history files.

A database consists of linked tables that form an overall datastructure. A data base management system is a collection oftools, features, and interfaces that enable users to add, update,manage, access and analyse data in a database.

Slide 30

Data Design

Database Management Systems (DBMS)These are more powerful and flexible than traditional file – orientedsystems. A database environment offers scalability support fororganisation-wide access, economy of scale, data sharing among usergroups, balancing of conflicting user requirements, enforcement ofstandards, controlled redundancy, effective security, flexibility, betterprogrammer productivity and data dependence.

Database management system components include interfaces forusers, database administrators and related systems, a datamanipulation language; a scheme, and a physical data repository.Other data management techniques include data warehousing, whichstores data in an easily accessible form for users access and datamining which looks for meaningful patterns and relationships amongdata.

Slide 31

Data Design

Data Design Task

Data design tasks include creating an initial entity –relationship diagram; assigning data elements to an entity,normalising all table designs; and completing the datadictionary entries for files, records and data elements. Filesand database tables should be sized to estimate theamount of storage space they will require. File anddatabase control measures include limiting access to thedata, data encryption, backup/recovery procedures, audit-track files and internal audit fields.

Slide 32

Questions

Individual Assignment:

1. What factors would you consider when designing adatabase

2. Design a database of students in your class. The data itemsshould include student name, student ID, course, facultydepartment, hall of residence. Using the student ID,manipulate this data use on your computer screen

Forum Question

Describe the r ole of data design in a systems development project

Slide 33

References

• Checkland, P. (1999). System Thinking, System Practice. Chiches:John Wiley.

• O’Brien, J. A. (2003). Introduction to Information Systems:Essentials for E-Business Enterprise. Boston: Irwin

• O’Leary, I. and O’leary, T. I. (2004). Computing Today. Boston: McCraw-Hill

• Rowley, J. (1990). The Basics of Systems Analysis and Design forInformation Managers. Ludin: Clive Bingley

• Whitten, J. et al (2000). Systems Analysis and Design Methods. 6thed., Boston: Mc Craw-Hill

Slide 34