tools of structure analysis 2003

8/14/2019 Tools of Structure Analysis 2003

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Tools Of Structured

Analysis


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Group Members


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Introduction

Traditional tools have some limitations.

So to overcome these limitations

structured tools are used.

Structured tools such as a Data Flow

Diagram(DFD), Data dictionary &

Structured English, provide alternative

ways of designing a candidate system.


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What is StructureAnalysis?

Definition :

its a set of techniques andgraphic tools that allow the analysis todeveloped a new kind of system

specification that are easily understandableto the user.

Goals :

4. Use graphic whenever possible.

5. Differentiate between logical and physicalsystem.

6. Build a logical system.


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Tools Of StructureAnalysis

Data Flow Diagram

Data Dictionary

Structured English

Decision Tree

Decision Table


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Data Flow Diagram(DFD)

Data flow diagram supports 4 main activities:

Analysis: DFD used to determine

requirements of users

Design: DFD used to map out plan andillustrate solutions to analysts and users while

designing a new system

Communication: DFD is simple and easy to

understand to analysts and users;

Documents: DFD used to provide special

description of requirements and system

design.


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Main components ofdata flow diagram

Process Flow

Storage

External factors

Internal factors.

You can construct DFD of system with thefollowing guidelines:

Choose meaningful names for processes, flows,stores, and terminators.

Number of processes.

Re-draw the DFD many times .

Avoid overly complex DFD.


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Advantage &Disadvantage

Advantage :

1.Its shows a minimum contents of datastores.

2.Its a quite effective, to clear the design tothe user.

3.Its analyst to use the national language forcommunication.

Disadvantage :

1.It required the large number of iterations,that often are required to arrive at the mostaccurate and complete solution.


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Library

Management

System

Readers

Management

Documents

Management

Documents

Looking up

B/R ticket

Management

System

Reports

New readerreceiving

Dept_noChecking

Newdepartment

registerReader_noallocating

DocumentsClassifying

New booksInserting

Newmagazines

inserting

Bookslooking up

Magazineslooking up

B/R ticketReceiving

Checking

Replying

DocumentReport

DepartmentReport

Overdue

Readers

Function Hierarchy Diagram


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Data Dictionary

o In DFD we give name to data flow,process , data store.

oAlthough the names are descriptive of

the data, the do not give detail.oSo a structured place is build to keep

the detail, this place is called datadictionary.

o Its a regorous definition of all DFD.


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Advantages of DataDictionary

Its works as a valuable reference.

It improves the communication between

analysis and user.

it can be use to compare the data

description.

Data dictionary can be use for cross

referenced. Its used in building a database.


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Logical Data DescriptionHierarchy


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Decision Tree

Decision TreesGraphical representation of the conditions,

actions, and rules found in a decision tree.

Whether to use a decision table or tree it isa matter of personal preference.


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Structured English

Structured EnglishMight look familiar to programming students

because it resembles pseudo code


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Decision Tables

Decision Tables

It define problems and action that has to be

taken.

Its a relationship between condition andaction.

It has two parts: stub and entry.

Stub has two parts, Entry has two parts,1.Condition Stub 1.Condition Entry

2.Action Stub 2.Action Entry


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Decision Tables


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Summary

Data and process modeling involves five

main tools: Data Flow Diagrams(DFD), a

Data Dictionary, Structure English,

Decision Tree and Decision Table. Data flow diagrams (DFDs) graphically

show the movement and transformation of

data in the information system.

The data dictionary is the central

documentation tool for structured analysis.


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Thank

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