1. Flowchart and Data Flow Diagrams
Supplemental A
Flowchart and Data Flow Diagrams

2. Purpose and Description
Flowchart are used to describe an entire information system or some portion of it. System flowcharts are used to illustrate the entire information system
The different types of flowcharts are as follows
Systems flowcharts chow the entire system configuration, including the documents data flows, and processes of a system.
Document/procedure flowcharts show the creation, flow and destination of documents within a system and the procedures performed on them.
Hardware flowcharts show the hardware configuration of a system.
Program flowcharts show the logic and processing steps of a computer program.

3. The Basic Elements of Systems/Document Flowcharts
Document flowcharts consists of three simple graphical elements that can be combined to represent various types of information flows and processes:
Symbols
Flow lines
Areas of responsibility
Flowcharting symbols and methods can vary widely across professions and organizations. There is no one set of generally accepted flowcharting principles and symbols.

4. EXHIBIT A-1 Document Flow in a Manual Accounting System
subsidiary ledger
Prepare
Sales
invoice 3 2
Source
Documents N
Employee Involved
In the Transaction
Record transaction journal entry
Record 3
Document
Investors/creditors
Transaction journal
General Ledger
Post Journal entries to ledgers
Financial statements
Trial
balance
Accounting Department
N = Numeric
Adjust and Close
Ledger
Financial
Statement
Customer

5. Flowcharting element 1 : symbols A variety of symbols are used to represesnt the physical aspects of the document/data flows and processes of an information system.
Input and output: documents The documents symbol is used for all types of paper source documents that are processes by the system.

6. EXHIBIT A-2 Sales/Collection Document Flowchart3 2
Start
Prepare
Sales
invoice
Check
Customer
Credit
Sales N
Sales Clerk
From
Payment
Endorse check and prepare remittance advice
Remittance advice 1
Record transaction and update ledger
Transaction journal
Accounts receivable ledger
Cash Receipts Clerk
Account Receivable Clerk
N = Numeric

7. EXHIBIT A-3 Flowchart Symbols: Documents4 3
Invoice 2
Shipping 1
receipt
Sales
Sales
(A)
Single
Document
(B)
Non processed
Documents
(C)
Overlapping symbols
Same documents
(D)
Two overlapping
Symbols, same documents
(E)
Two overlapping Symbols,
Different documents

8. EXHIBIT A-4 Flowchart Symbols
Online Manual
Device
(B)
Terminal
Display
(C)
I/O
(Input/Output)
(D)
Manual
process
(E)
Online
Computer A N
Permanent
File
Temporary
file
(F)
Offline or
Non computer
(G)
Offline
Paper
(H)
data
storage
(I)
Disk
(J)
Magnetic
tape

9. EXHIBIT A-5 More Flowchart Symbols
From
bank To
customer
Start 1
Indicates the flow will
Continue at on-page connector 1
Indicates where the flow continues
from on-page connector 1
(C)
On-page
connectors
(A)
Enter/Exit
System
(B)
(or end) process
(E)
Annotation
(F)
Decision
(G)
Calculator
Register tape
(H)
Physical
Object
(I)
Flow
Lines
(J)
Communication
Link
p.4
On page 2:
To page 4
Connector 1
On page 4:
p.2
From page 4
(D)
OFF-page

10. Summary
The flowchart is one of the easier types of documentation for information customers and management to understand. Often auditors use system, document and procedure flowcharts to understand business and system controls in an environment.
The primary weakness of the flowchart is that it is tied to physical information flows and system characteristic that hide the procedural essence of the system.
Data flow diagrams are a useful tool for documenting the conceptual aspects of an information system.

11. DATA FLOW DIAGRAMS (DFD)
A second documentation tool is the data flow diagram (DFD). Data Flow Diagramming symbols are used for a variety of system analysis purposes, including graphically displaying the logical flows of data through a process. Unlike flowcharts, which represent the physical components of an information system, data flow diagrams can provide a more conceptual, nonphysical display to the movement of a data through a system. Data flow diagrams disregard such things as organizational units, the computer on which the data are processed, and the media on which the data are stored.

12. Data Flow Diagram Symbols
Data Flow diagrams include four symbols : process, data inflow sources and outflow sinks (destinations), data stores and data flow lines. Like flowcharting, there are variations on some of the symbols.

13. EXHIBIT A-6 Data Flow Diagram Symbol
Process
(B)
Sources/Sinks
(C)
Data Store
(D)
Data Flow Lines
DeMarco and Yourdan symbols
Gane and Sarson symbols

14. EXHIBIT A-7 Data Flow Diagramming Rules
Rule Number 4 5 7 8 9 13 11 14 15 16
Incorrect
Correct A C B
J. Hoffner, J. George, and J. Valacich, Modern System Analysis and Design (Reading, MA: Benjamin/Cummings, 1996), p. 31

15. EXHIBIT A-8 Context Diagram Example
Levels of Data Flow Diagrams
The highest level of data flow diagrams is the context diagram
EXHIBIT A-8 Context Diagram Example
Customers
Sales/Collection
System
Decision
Makers
Order
Bill
Payments
Desired
Information

16. EXHIBIT A-9 Level Zero DFD Example Customers
2.0
Process
shipments to
customers
Decision
Makers
Order
Bill
Payments
Desired
Information
1.0
orders
3.0
from
Due data
Subsequent level DVDs The process identified in the context diagram is divided
into the more detailed processes performed within the system

17. EXHIBIT A-10 Level –One DFD Example Approved order Order data
1.1
Approve and
record customer
order data
1.2
Generate
information
about orders
Customer order data
Order
Shipping
Request
data
Approved order
Order data
Desired Information

18. EXHIBIT A-11 Level –Two DFD Example data 1.1.1 Receive from 1.1.2
1.1.4
Record
order data
1.1.2
Check
customer
status
Customer data
Order
Approved
order
Inventory
availability
1.1.1
Receive
from
1.1.3
inventory
Customer
credit status
data

19. Example Data Flow Diagram
EXHIBIT A-12
Comparative Example-Version 1 N 2
Example Data Flow Diagram
Review time
cards
Time
Cards
Example Flowchart
A = Alphabetic A
Record Wages
Employee
Earning
Records
Factory
Supervisor
Review
Time
Employee earnings
records
Time card file
(alpha)
supervisor
Accounting
payroll clerk
Reviewed
Time cards

20. Example Data Flow Diagram
EXHIBIT A-12 Comparative Example-Version 2 N 2
Example Data Flow Diagram
Review time
cards
Time
Cards
Example Flowchart
A = Alphabetic
Factory
Supervisor
Review
Time
Employee earnings
records
Time card file
(alpha)
supervisor
Accounting
payroll clerk
Reviewed
Time cards
Key in
time cards
Record
wages A
Earning
master file

21. Example Data Flow Diagram
EXHIBIT A-14 Comparative Example-Version 3 N 2
Example Data Flow Diagram
Review time
cards
Time
Cards
Example Flowchart
A = Alphabetic
Factory
Supervisor
Review
Time
Employee earnings
records
Time card file
(alpha)
supervisor
Accounting
payroll clerk
Reviewed
Time cards
Key in
time cards
Record
wages A
Employee
Earning
master file