ATG 383 - CHAP 3
Data Flow Diagrams and
Flow Charts
Spring 2002
ATG 383 - Chapter 3
Overview

Introduction
» Why master system documentation
techniques?
Drawing DFDs
 Drawing Flowcharts

ATG 383 - Chapter 3
Why learn how to document a
system’s operation?
?
ATG 383 - Chapter 3
Data flow diagrams show
what a system does
while flowcharts show
how the work is done.
4 DFD Symbols - page 59
ATG 383 - Chapter 3
EXAMPLE DFD
CPAs send research requests to the AICPA library and
receive back bibliographies related to their questions. When the
request is received, the chief librarian checks the membership
data base (since searches are only done for members.) She also
reviews the requests to determine that it is appropriate. Rejected
requests are returned to the sender.
Approved requests are forwarded to a research librarian .
He searches the periodical index and prepares the
bibliography. This is sent to the CPA.
ATG 383 - Chapter 3
Inputs?
CPAs send research requests to the AICPA library and
receive back bibliographies related to their questions. When the
request is received, the chief librarian checks the membership
data base (since searches are only done for members.) She also
reviews the requests to determine that it is appropriate. Rejected
requests are returned to the sender.
Approved requests are forwarded to a research librarian .
He searches the periodical index and prepares the
bibliography. This is sent to the CPA.
ATG 383 - Chapter 3
Outputs?
CPAs send research requests to the AICPA library and
receive back bibliographies related to their questions. When the
request is received, the chief librarian checks the membership
data base (since searches are only done for members.) She also
reviews the requests to determine that it is appropriate. Rejected
requests are returned to the sender.
Approved requests are forwarded to a research librarian .
He searches the periodical index and prepares the
bibliography. This is sent to the CPA.
ATG 383 - Chapter 3
Context Diagram
CPA
AICPA Library System
CPA
ATG 383 - Chapter 3
Data moving through system?
CPAs send research requests to the AICPA library and
receive back bibliographies related to their questions. When the
request is received, the chief librarian checks the membership
data base (since searches are only done for members.) She also
reviews the requests to determine that it is appropriate. Rejected
requests are returned to the sender.
Approved requests are forwarded to a research librarian .
He searches the periodical index and prepares the
bibliography. This is sent to the CPA.
ATG 383 - Chapter 3
Processing Steps
CPAs send research requests to the AICPA library and
receive back bibliographies related to their questions. When the
request is received, the chief librarian checks the membership
data base (since searches are only done for members.) She also
reviews the requests to determine that it is appropriate. Rejected
requests are returned to the sender.
Approved requests are forwarded to a research librarian .
He searches the periodical index and prepares the
bibliography. This is sent to the CPA.
ATG 383 - Chapter 3
Files used?
CPAs send research requests to the AICPA library and
receive back bibliographies related to their questions. When the
request is received, the chief librarian checks the membership
data base (since searches are only done for members.) She also
reviews the requests to determine that it is appropriate. Rejected
requests are returned to the sender.
Approved requests are forwarded to a research librarian .
He searches the periodical index and prepares the
bibliography. This is sent to the CPA.
ATG 383 - Chapter 3
Summary


CPA sends research requests
Chief librarian
»
»
»
»

checks membership database
reviews requests
approved requests to research librarian
rejects returned to sender
Research librarian
» searches periodicals index

Bibliography sent to CPA
ATG 383 - Chapter 3
Level 0 DFD
CPA
1.0
Review
Request
2.0
Create
Biblio.
CPA
ATG 383 - Chapter 3
FLOWCHARTING GENERAL
We are concerned with document
flowcharts.
 These describe the physical
operation of a system.
 Variety of symbols needed to depict
actual operations.
 See Figure 3.8, page 69

ATG 383 - Chapter 3
Flowcharting Symbols - p. 69
ATG 383 - Chapter 3
Flowcharting Symbols
ATG 383 - Chapter 3
Flowcharting Symbols
ATG 383 - Chapter 3
Flowcharting Symbols
ATG 383 - Chapter 3
Example 1
Payroll supervisor reviews a time
card.
ATG 383 - Chapter 3
Example 2
 Personnel
department updates
the personnel files based on
information from a new
employee’s application. The
application is filed alphabetically.
Two copies of a new employee
form are sent to department x.
ATG 383 - Chapter 3
Example 3
Batches of time cards are keyed
into the payroll master disk file.
Then the time cards are filed by
date.
ATG 383 - Chapter 3
Example 4
The personnel manager receives a
change of status form which is
keyed into the system and updates
the master disk file. The system
creates a confirmation of the
change. The personnel manager
compares this to the original
request. Both documents are sent
to the employee.
ATG 383 - Chapter 3
To Have Success With
Drawing DFDs & Flowcharts
Learn the symbols
 Understand the system
you are diagramming
 Practice

ATG 383 - Chapter 3