IT 21103/41103 System Analysis & Design. Chapter 07 System Design Phase.

IT 21103/41103IT 21103/41103

System Analysis & DesignSystem Analysis & Design

Chapter 07Chapter 07

System Design PhaseSystem Design Phase

System DesignSystem Design

““Good Design has no SubstituteGood Design has no Substitute

Bad Design no Escape”Bad Design no Escape”


Users become very important Users become very important during this phase….during this phase….


……You must define what the user You must define what the user actually needs in the new system.actually needs in the new system.


Key Concern for this Phase:Key Concern for this Phase:

““The USER comes first”The USER comes first”


Design Phase Termination:Design Phase Termination:

When the user is satisfied that the When the user is satisfied that the system will perform as intended or system will perform as intended or

when monetary and/or time when monetary and/or time constraints are exceeded.constraints are exceeded.


System Types:System Types:

Transaction-Processing SystemTransaction-Processing System

Real-Time DataReal-Time Data

Batch ProcessingBatch Processing


Management Information SystemManagement Information System

(MIS)(MIS)

Enterprise Data Enterprise Data


Decision Support System (DSS)Decision Support System (DSS)

Decision SupportDecision Support


Local Area Networked Information Local Area Networked Information System (LAN-IS)System (LAN-IS)

Local CommunicationsLocal Communications


Wide Area Networked Information Wide Area Networked Information System (WAN-IS)System (WAN-IS)

Wider CommunicationWider Communication


Expert Systems Information Expert Systems Information NetworkNetwork

Analyze & Diagnose ProblemsAnalyze & Diagnose Problems


Strategic Information SystemStrategic Information System

Outside AnalysisOutside Analysis


Alternative Approaches:Alternative Approaches:

(See Figure 7-5, Page 179)(See Figure 7-5, Page 179)


Structured Design:Structured Design:

Breaking the problem into more Breaking the problem into more manageable partsmanageable parts


Structured Design:Structured Design:

4GL – 44GL – 4thth Generation Language Generation Language

Modular DesignModular Design

Object ProgrammingObject Programming


Object-Oriented Design:Object-Oriented Design:

Analysts skip the DFD & ERDAnalysts skip the DFD & ERD

Develop the OM insteadDevelop the OM instead

(USD, Menu-Tree, (USD, Menu-Tree,

System Flowchart)System Flowchart)


Object-Oriented Design:Object-Oriented Design:

Makes system design easier when Makes system design easier when using 4GL programming languagesusing 4GL programming languages


Joint Application Design:Joint Application Design:

Developed in the mid-1980’sDeveloped in the mid-1980’s

Intense Formal Design Intense Formal Design

Workshop SessionWorkshop Session


Joint Application Design:Joint Application Design:

Can also have several small Can also have several small informal sessions over the period of informal sessions over the period of

the analysis and design phasesthe analysis and design phases


Design Specifications:Design Specifications:

Gives the User the first look at the Gives the User the first look at the system, and the Analyst a blueprint system, and the Analyst a blueprint

to build the systemto build the system


Design Specifications:Design Specifications:

Develop a New USDDevelop a New USD

Enhances the previous USD to Enhances the previous USD to more closely match the users needsmore closely match the users needs


Design Prototyping:Design Prototyping:

All Show – gives the user a All Show – gives the user a practical look at the system during practical look at the system during

the design processthe design process


Project Deliverable:Project Deliverable:

The Preliminary PresentationThe Preliminary Presentation

A Formal Oral and Written Report A Formal Oral and Written Report


Preliminary Presentation: Preliminary Presentation: WrittenWritten

Summary of Project RequirementsSummary of Project Requirements

Overview of General Design Overview of General Design ConceptsConcepts

Proposed TimetableProposed Timetable

Proposed Project Budget Proposed Project Budget


Preliminary Presentation: Preliminary Presentation: OralOral

IntroductionsIntroductions

Visuals from Written ReportVisuals from Written Report

Questions & Answer PeriodQuestions & Answer Period

Preview of the Next StepPreview of the Next Step


The Presentation:The Presentation:

Extremely Important toExtremely Important to

UsersUsers

AnalystsAnalysts

Project SupportersProject Supporters


The Design Review SessionThe Design Review Session

Requires Careful DocumentationRequires Careful Documentation


Form Design:Form Design:

Create specific form designs to be Create specific form designs to be used in the systemused in the system



Today is mostly Graphical in natureToday is mostly Graphical in nature

Always on – ready for user inputAlways on – ready for user input

May be based on Internet designMay be based on Internet design



Source DocumentsSource Documents

Must include some way for users to Must include some way for users to receive help about the new forms receive help about the new forms and a way to backup these forms and a way to backup these forms

for auditing purposesfor auditing purposes


Graphical User Interface Dialogs Graphical User Interface Dialogs (GUIDs)(GUIDs)

Instructs users how to use the form, Instructs users how to use the form, and records their selections and and records their selections and

inputsinputs



Should have a consistent Should have a consistent

look & feellook & feel



Should provide Entrance to the Should provide Entrance to the database systemdatabase system



Correct Errors ASAP, do not wait to Correct Errors ASAP, do not wait to look for errors when the system is look for errors when the system is

completedcompleted


Other Considerations:Other Considerations:

Design the system for the user not Design the system for the user not the analystthe analyst

Make allowances for users who do Make allowances for users who do not have adequate knowledge of not have adequate knowledge of

computer technologycomputer technology



Make the Design as easy as Make the Design as easy as possible, but still covers all the possible, but still covers all the required system inputs/outputsrequired system inputs/outputs



Forms need to be designed for the Forms need to be designed for the novice computer usernovice computer user

Think about programs you have Think about programs you have used that were difficult to used that were difficult to

understandunderstand



DOCUMENT EVERYTHING YOU DOCUMENT EVERYTHING YOU DO DURING THIS PHASEDO DURING THIS PHASE

Documentation is required during all Documentation is required during all phases, but this phase is most phases, but this phase is most

critical for keeping current critical for keeping current documentation.documentation.



This phase is critical to the success This phase is critical to the success of your project…make it countof your project…make it count

““Put yourself in the shoes of the Put yourself in the shoes of the user and stay there”user and stay there”


QuestionsQuestions


Assignment # 07Assignment # 07

Page 204-205Page 204-205

Parts I & IIParts I & II

Due: Nov 15Due: Nov 15thth

IT 21103/41103 System Analysis & Design. Chapter 07 System Design Phase.

Documents

Transcript of IT 21103/41103 System Analysis & Design. Chapter 07 System Design Phase.