ATG 383 - CHAP 3

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ATG 383 - CHAP 3

• Data Flow Diagrams and
• Flow Charts
• Spring 2002

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Overview

• Introduction
• Why master system documentation techniques?
• Drawing DFDs
• Drawing Flowcharts

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Why learn how to document a systems operation?
?
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Data flow diagrams showwhat a system doeswhile
flowcharts showhow the work is done.
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4 DFD Symbols - page 59
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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.
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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.
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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.
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Context Diagram
CPA
AICPA Library System
CPA
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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.
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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.
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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.
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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

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Level 0 DFD
CPA
1.0 Review Request
2.0 Create Biblio.
CPA
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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

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Flowcharting Symbols - p. 69
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Flowcharting Symbols
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Flowcharting Symbols
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Flowcharting Symbols
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Example 1

• Payroll supervisor reviews a time card.

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Example 2

• Personnel department updates the personnel files
  based on information from a new employees
  application. The application is filed
  alphabetically. Two copies of a new employee form
  are sent to department x.

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Example 3

• Batches of time cards are keyed into the payroll
  master disk file. Then the time cards are filed
  by date.

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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.

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To Have Success With Drawing DFDs Flowcharts

• Learn the symbols
• Understand the system you are diagramming
• Practice