Preview

Dfd to Structure

Powerful Essays
Open Document
Open Document
1477 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Dfd to Structure
DFD to Structure Charts

Georgia State University

DFDs to Structure Charts

First Level Data Flow Diagram
0 Library System

1

Book Catalog

3 2

Borrowers List

Georgia State University

DFDs to Structure Charts

Functional Decomposition
0 Library System 1 2 3

2.1

2.2

Georgia State University

DFDs to Structure Charts

Structure Chart
Structure Chart Example Q: Where do the modules come from?

Logical Design
Executive Module 'Update File' Top because it calls all others none call it at this level

Module 1 e.g. Read

Module 2.. e.g. Update

Module n e.g. Write

Open FIle
Georgia State University DFDs to Structure Charts

Structure Chart
Structure Chart Example Q: Where do the modules come from?

Physical Design

2
Executive Module 'Update File' Top because it calls all others none call it at this level

1

3
Module n e.g. Write

Module 1 e.g. Read

Module 2.. e.g. Update

Open FIle
Georgia State University DFDs to Structure Charts

DFD to Structure Charts?
0 Library System

1

Book Catalog

?
Module 1 e.g. Read Open FIle

Structure Chart Example Q: Where do the modules come from?

3

2

Executive Module 'Update File' Top because it calls all others none call it at this level

Module 2.. e.g. Update

Module n e.g. Write

Borrowers List

Georgia State University

DFDs to Structure Charts

Why Divide Things Up?
Logical Design
– Simplifies understanding
“divide and conquer”

– Allows parallel development

Physical Design
– Separately compilable modules one change should not require a complete build

Georgia State University

DFDs to Structure Charts

Basic Design Goals
Fitness for purpose
– the system must work, and work correctly – it should perform all tasks as specified within the constraints of the resources

Robustness
– the design should be stable against changes to features such as file or data structures

Georgia State University

DFDs

You May Also Find These Documents Helpful

Related Topics