Week 11 & 12 - Tools for System Planning and Analysis

8/4/2019 Week 11 & 12 - Tools for System Planning and Analysis

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Sistem Maklumat Dlm Organisasi

Chapter 6.1

Planning and System

Analysis Tools

Week 11 & 12


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Objectives

At the end of this topic, studentswill be able to:

Explain the function of flow chart, dataflow diagram, entity relationshipdiagram, Gantt chart and PERT chart

Construct flow chart, data flowdiagram, entity relationship diagram,Gantt chart and PERT chart


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Contents

5.1.1 Introduction

5.1.2 Flow Chart

5.1.3 Data Flow Diagram (DFD)5.1.4 Entity Relationship Diagram

(ERD)

5.1.5 Gantt Chart & PERT Chart


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5.1.1 Introduction


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Introduction

Revision about SDLC

A development of information

system consists of phases,activities, techniques and tools

What is an information systemdevelopment tools?


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Introduction

Tool is a model or diagram used todescribe about an informationsystem from various perspectives

Tools can be categorized into twotypes:

Tools for system analysis

Tools for planning the systemdevelopment


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Introduction

Tools for system analysis Entity relationship diagram

Data flow diagram

Flow chart

Tools for planning the system

development Gantt chart PERT chart


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5.1.2 Flow Chart


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Flow Chart

A tool to describe in detail about processesinvolve in an information system

In computer science area, flow chart isused to show the sequence of operations ina computerized system

It is among the earliest diagram to bedrawn in the early phase of systemdevelopment

Among the software to help creating flowchart are Smart Draw, Corel iGrafxFlowCharter and Microsoft Visio


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Flow Chart

Flow chart symbols

Symbol Descriptions

Start or end of one programCalculation or process

Input or output for one operation

Testing and decison making

Flow of direction


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Flow Chart

Exampe1

Draw a flow chart to describe theprocess of 2 + 5.

Operation and process in sequence start

read input (2 and 5)

adding Operation (2 + 5) get output (7)

end


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Flow Chart

Start

End

Input 2 and 5

2 + 5

Output 7


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Flow Chart

Example 2

Draw a flow chart to describe the

process of making a decision tochoose the right way to go homefrom an office


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Flow Chart

Operation and the processes according tothe sequence Go out from office

Check the weather and time Is the weather ok? If no, choose an alternative

way. If yes, proceeds.

Is it 5 pm already? If no, choose an alternativeway. If yes, proceeds.

Check the flow of traffic at the main road. Is there any traffic jam? If yes, choose an

alternative way. If no, use the main road.

Safely arrive at home.


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No

No

No

Yes

Yes

Get out from office

Safely arrive at home

Check weather & time

Weather ok?

5 pm already?

Check the flow of traffic at the

main road

Yes

Traffic Jam?

Choose alternative roads

Choose the main road


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Flow Chart

Advantages Helps to understand the flow of operations in the

system to be developed

Helps to analyze and solve problems especially

related to the development of a computerizedsystem

Helps system documentation

Facilitate programmer in writting programs basedon the processes and flow involve

System maintenance will be easier since flowchart provides a visual representation of modulesinvolve in a system


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Flow Chart

Disadvantages

Flow chart could be difficult to helpunderstanding processes in a complex system

Less flexible especially when there is a part ofa system needs to be modified.

Any modification will require system analyst toredraw a new flow chart

Does not show in detail the structure of one

system and all the data flows involve


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5.1.3 Data Flow Diagram


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Data Flow Diagram

Data Flow Diagram (DFD)

A tool that is used to picture processesand data flows in one system

Also known as Buble Chart,transformation graf or process model.

DFD shows the details in terms of theprocesss components and data flows in

and out from each component.


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Data Flow Diagram DFD can be created in numbers of levels. It starts with Context diagram and proceeds with

DFD level 1, level 2 and the rest (level n) Context diagram shows the entire system as one

main process or as a black box. It only shows oneprocess, major data flow to and out from the systemand the elements that provides (source)and receives(sink) the data flow.

DFD Level 1 is an explosion of the main processgiven in a context diagram. It shows the subprocesses under the main system.

DFD Level 2 is an explosion of each of the subprocesses highlighted in DFD Level 1

There are different versions of DFD symbols and oneof them is given by Gane and Sarson.


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Data Flow Diagram

DFD Symbol

Environmental elements

Also known as a Source and Sink

Refers to an element outside the systemsboundary, but is still associated with thesystem in terms of providing data to thesystem or receiving data from the system.


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Data Flow Diagram

DFD Symbol

Process

Process is an activity that transforminput to output. It is normally describedwith verb and object.


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Data Flow Diagram

DFD Symbol

Data storage

A place or an object that is used tostore data, either permanent ortemporary.


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Data Flow Diagram

DFD Symbol

Data Flow

Refers to the flow of data orinformation to or from the system

Data flow shows relationship betweensource and sink, process and datastorage.


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Data Flow Diagram

Example 1Draw a context diagram and DFD Level 1for a university application system. Theprocess begins when student sends an

application form that contains his or herpersonal data and qualification. Thesystem will process the application andchoose the qualified students. In the nextprocess, the system will send a letter to

student to notify whether the applicationis accepted or rejected.


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Data Flow Diagram

Identifying elements of DFD:

Environmental elements (source/sink):student/applicant

Process: choose the qualified student

Data Storage:Applicant File/ Database

Data Flow: application form, letter ofnotification, information on the qualifiedstudents, information about applicants


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Data Flow Diagram

Successful applicantsLetter ofNotification

Application formStudent

UniversityApplicationSystem

Applicant

File

Context Diagram


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Data Flow Diagram

Successful applicants

Letter ofNotification

Application formStudent

1.0Check

StudentQualification

ApplicantFile

2.0

Notify theresults

DFD Level 1


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Data Flow Diagram

Example 2

Draw a context diagram and DFD Level 1to show the process of opening a saving

account in Bank Y. Customer must fill in aregistration form and submit back to thebank.The system will record the customerinformation and store it in the customer

file.System will later print out the savingbook and give it to customer.


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Data Flow Diagram

Identifying DFD elements :

Source/ Sink: Customer

Process: Process customersregistration

Data Storage: Customer File/Database

Data flow: application form, money,saving book, customer information


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Data Flow Diagram

Customer informationSaving book

Registration form

Money

Customer

CustomerRegistration

System

Customer

file

Context Diagram


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Data Flow Diagram

Registration

information

Customerinformation

Saving book

Registration form

Money

Customer

1.0Process

registrationform

Customer

file2.0

Printsavingbook DFD Level 1


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Data Flow Diagram

Advantages

An effective tool to describe processes anddata flow in an information system

Disadvantages DFD is not enough to help people understand

one system. Both flow chart and DFD must beused together with Entity relationship diagram(ERD) to help creating a complete and

comprehensive planning and system analysis.


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5.1.4 Entity RelationshipDiagram


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Entity Relationship Diagram

Entity Relationship Diagram (ERD) Is used to model data Data in a system will be classified into groups that

is knowned as an entity

Identify relationship between entities ERD is important to help system analyst

determine data to be stored in database A good ERD will produce an information system

with comprehensive and organized databasestructures


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ERD Symbol

Entity

Anything that has data to be manipulated by

the system. Entity can be environmentalelements, resources or transaction.

Examples of entity are students, course,registration, book and organization.

Entity has characteristics known as atribute


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ERD Symbol

Relationship

Relationship or association that existsbetween two entities.

Relationship is normally representedwith verb

Examples are register, is supplied,made


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Types of relationship 1:1 (one-to-one)

An instance of one entity has a relationship with aninstance of another entity. For example, onestudent has only one id card.

1:M (one-to-many)

An instance of one entity has a relationship withmore than one instance of another entity. Forexample, one student can register more than onecourse.

M:N (many-to-many) Many instances have relationship with many

instances of another entity. For example, manycustomers buy many products.


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Example 1

Create an ERD to show the entity

relationships in Course registrationsytem. Student can register a fewcourses for the next semester.


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Identify ERD elements

Entity : Studentand Course

Relationship: Student register course

Type of relationship: one student canregister many courses

Atributtes : Student [matric no., name,program, semester, address],

Course[code, name, day, time,prerequisite, lecturer]

Primary Key: Student [matric no.],Course[code]


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M1STUDENT COURSE

Register

A SIMPLE ERD


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M1PELAJARMatric no.nameaddressprogram

semester

COURSEcodenametimedayprerequisitelecturer

Register

ERD


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Example 2

Create an ERD for a database tostore information about book,author and distributor in SyarikatPenerbitan Indah.


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Identify ERD elements

Entity : Book, Author and Distributer

Relationship : is written, is distributed

Type of relationship:A book is written by many

authors and many books are distributed bymany sidtributer

Attributes : Book [ISBN, title, author,price]Author[author code, name, address, phone no.],Distributer[distributer code, name, address,

phone no.] Primary key: Book[ISBN], Author [author code],

Distributer [distributer code]


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Is

written

AUTHOR

1

M

MMBOOK DISTRIBUTERIs

distributed

A Simple ERD



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MM

DISTRIBUTERDistributer codeNameAddress

Phone no.

Is

distributed

Is written

AUTHORAuthor codenameaddress

Phone n o.

1

M

BOOKISBNtitleauthor

price

ERD


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Advantages

ERD is an effective tool to helpdesigning a relevant database that met

systems requirement. It is been widely used to model data

required in an information system


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5.1.5 Gantt Chart & PERT Chart


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Gantt Chart

Gantt Chart has been introduced in 1917by Henry L. Gantt, an American engineerand social scientist. The chart has beenused to control production. Until today,Gantt Chart is still being used for thepurpose of project planning andmanagement.

In general, Gantt Chart provides a

graphical chart that shows scheduling tohelp planning, monitoring, and trackingresources in a project.


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Gantt Chart

A simple Gantt Chart can be drawn on apiece of paper

However, people today have manychoices to use varieties of software tocreate Gantt Chart. Among the softwareavailable are Microsoft Project, MicrosoftVisio and SmartDraw.


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Gantt Chart

Carta Gantt contains numbers of vertical bars thatshow the required and expected time to completean activity in one IS system development.

The bar represents the time in unit such asmonths, weeks, days, hours or minutes. In IS

development project, the unit normally used iseither week or month.

Each bar represents one activity in the systemdevelopment.

Gantt chart can clearly describe the status of oneproject, whether it follows the time given or not.


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Gantt Chart

Before developing a Gantt chart, the teammust identify the activities involve in oneproject.

A hierarchical chart known as WorkBreakdown Structure (WBS) can be usefulto help the team structures the activities

WBS can help the team identify activities

and expected time to implement andcomplete each activity.


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Gantt Chart

Example 1

You are asked to develop a PayrollSystem for Human ResourcesDepartment in UUM. You haveselected SDLC to develop thesystem. Create WBS and use it as a

guide to help you create Ganttchart.


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Gantt Chart

Solution

SDLC has eight phases:

Investigation Phase (Fasa Penyiasatan)- 3 wks Analysis Phase (Fasa Analisis)- 4 wks Design Phase (Fasa Rekabentuk)- 4 wks Coding Phase (Fasa Pengaturcaraan)- 6 wks Testing Phase (Fasa Pengujian)-1 wks

Implementation Phase (Fasa Perlaksanaan)- 2 wks Operation Phase (Fasa Operasi)- 2 wks Maintenance Phase (Fasa Penyelenggaraan)- 2 wks


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Gantt ChartPayroll System

Investigation OperationDesign Testing

Analysis MaintenanceCoding Implementation

Feasibility Studies


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Gantt Chart


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Gantt Chart

Advantages

Able to identify a duration of time required tocomplete one activity, together with theallocated money and human resources.

Disadvantages

Unable to show the relationship betweenactivities connected to complete one phase

Unable to show the most critical activity in a

project.


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PERT Chart

PERT Chart (Program Evaluation andReview Technique)

Also known as a Network Diagram.

Has been used in late 1950s in theplanning and monitoring weaponsdevelopment project.

PERT chart was used at that time to showthe connection between activities that

have been determined to complete theproject.


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PERT Chart

PERT chart components:

Activity

An activity is labeled with a simple name thatexplains the activity. The name is put on the top of

the line that connects two nodes. The time tocomplete the activity is put under the line. The unitfor the time can be in month, week or days.

Node

Node is represented by a small circle that is locatedat the beginning and end of an activity. A pair ofnodes form an activity. Number in a node isarranged in an ascending order.


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PERT Chart

Critical Path

It is represented by the sequence of connectedactivities that produce the longest overall time

All activities and nodes within this sequenceare referred to as being on the critical path

Changes in the critical path will give an impacton the whole time to complete the project

Any activity on the critical path that is delayed

in completion will result in delaying the finalcompletion of the project


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PERT Chart

Example 1

You are working as a marketing executiveat Syarikat Telekomunikasi Mutiara. The

company plans to implement prepaidtelecommunication services. To getinformation about the market for this newservice, you are assigned to survey the

market. Construct PERT chart to show theactivities involve and finally determinethe critical path.


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PERT Chart

Identify activities involve: Planning

The planning for survey (5 days) Questionnaires design (5 days)

Preparation Hire temporary workers (5 days) Training workers (3 days) Print questionnaires (2 days)

Implementation Distribute questionnaires (5 days) Analyze questionnaires(5 days)


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PERT Chart

G

5

F

5

E

2

D

3

C

5

B

5A

51 2

3

4

5 6 7


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PERT Chart

Identify the critical path:

A-B-E-F-G = 5 + 5 + 2 + 5 + 5 = 22

A-C-D-F-G = 5 + 5 + 3 + 5 + 5 = 23Critical path is A-C-D-F-G


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PERT Chart

Avantages

Helps managers to monitor an ongoingproject.

Using a critical path, managers candetemine the progress of a project bycomparing the actual time to completea project with the real time achieved to

complete


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End of Topic

Documents

Week 11 & 12 - Tools for System Planning and Analysis