Flowchart and Data Flow Diagrams

Supplemental A

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 followsSystems 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.

The Basic Elements of Systems/Document FlowchartsDocument flowcharts consists of three

simple graphical elements that can be combined to represent various types of information flows and processes:SymbolsFlow linesAreas 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.

subsidiary ledger

Prepare

Sales invoice

3

2

Source 1Documents

N

Employee Involved In the Transaction

Record transaction journal

entry

Record 3Document

Investors/creditors

Transaction journal

General Ledger

Post Journal entries

to ledgers

Financial statement

s

Trial balance

Accounting Department

N = Numeric

N

Adjust and

CloseLedger

Prepare Financia

l Stateme

nt

Customer

Customer

EXHIBIT A-1 Document Flow in a Manual Accounting System

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.

3

2

Start

Prepare

Sales invoice

Check Customer

Credit

3

2

Sales 1invoice

Customer N

Sales Clerk

From Customer

Payment

Endorse check and prepare

remittance advice

Remittance advice

N

2

Customer

1

Payment Payment

Record transaction and update ledger

2

N

Transaction journal

Accounts receivable

ledger

N

Cash Receipts Clerk

Account Receivable Clerk

N = Numeric

EXHIBIT A-2 Sales/Collection Document Flowchart

43

Invoice Invoice

2

Shipping 1receipt

Sales Invoice

4

Invoice

Sales 3 Invoice 2

(A)Single

Document

(B)Non processed

Documents

(C)Overlapping symbols

Same documents

(D)Two overlapping

Symbols, same documents

(E)Two overlapping Symbols,

Different documents

EXHIBIT A-3 Flowchart Symbols: Documents

(A)Online Manual

Device

(B)Terminal Display

(C)I/O

(Input/Output)

(D)Manual process

(E)Online

Computer process

A

N

Permanent File

Temporary file

(F)Offline or

Non computer process

(G)Offline Paper File

(H)Online data

storage

(I)Disk

storage

(J)Magnetic

tape storage

EXHIBIT A-4 Flowchart Symbols

EXHIBIT A-5 More Flowchart Symbols

Frombank

Tocustomer

Start

1

Indicates the flow will Continue at on-page connector 1

1

Indicates where the flow continues from on-page connector 1

(C)On-page

connectors

(A)Enter/Exit

System

(B)Start

(or end) process

(E)Annotation

(F)Decision

(G)Calculator

Register tape

(H)Physical Object

(I)FlowLines

(J)Communication

Link

p.4

1On page 2: To page 4

Connector 1

On page 4: 1

p.2Connector 1From page 4

(D)OFF-page connectors

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.

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.

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.

(A)Proces

s

(B)Sources/

Sinks

(C)Data Store

(D)Data Flow

LinesDeMarco and Yourdan

symbols

(A)Process

(B)Sources/

Sinks

(C)Data Store

(D)Data Flow

LinesGane and Sarson symbols

EXHIBIT A-6 Data Flow Diagram Symbol

Rule Number

4

5

7

8

9

13

11

14

15

16

Incorrect Correct

A

C

BA

AA

A

A

AA

A

B

B

A

EXHIBIT A-7 Data Flow Diagramming Rules

J. Hoffner, J. George, and J. Valacich, Modern System Analysis and Design (Reading, MA: Benjamin/Cummings, 1996), p. 31

Customers 0

Sales/Collection System

Decision Makers

Order

Bill

Payments

Desired Information

EXHIBIT A-8 Context Diagram Example

Levels of Data Flow Diagrams

The highest level of data flow diagrams is the context diagram

Customers

2.0Process

shipments to

customers

Decision Makers

Order

Bill

Payments

Desired Information

1.0Process

customers orders

3.0Process

Payments from

customers

Desire

d

Info

rmat

ion Payments

Due data

Desired

Information

EXHIBIT A-9Level Zero DFD Example

Subsequent level DVDs The process identified in the context diagram is divided into the more detailed processes performed within the system

EXHIBIT A-10Level –One DFD Example

1.1Approve and

record customer order data

1.2Generate

information about orders

Customer order data

Order

Shipping Request data

Approved order

Order data

Desired Information

1.1.4 Record

order data

1.1.2Check

customer status

Customer data

Order

Approved order

order

Inventory availability

1.1.1 Receive

order data from

customer

1.1.3 Check

inventory availability

Customer credit status

Inventory data Customer

order data

Approved order

EXHIBIT A-11Level –Two DFD Example

EXHIBIT A-12Comparative Example-Version 1

N

2

Example Data Flow Diagram

Review time cards

Time 1 Cards

Example Flowchart

A = Alphabetic

A

N

2

Time 1 Cards

Record

Wages

EmployeeEarning Records

Factory Supervisor

Review Time Cards

Review Time Cards

Employee earnings records

Time card file (alpha)

Factory supervisor

Accounting payroll clerk

Time cards

Reviewed Time cards

EXHIBIT A-12 Comparative Example-Version 2

N

2

Example Data Flow Diagram

Review

time cards

Time 1 Cards

Example Flowchart

A = Alphabetic

N

2

Time 1 Cards

Factory Supervisor

Review Time Cards

Review Time Cards

Employee earnings records

Time card file (alpha)

Factory supervisor

Accounting payroll clerk

Time cards

Reviewed Time cards

Key in time cards

Record wages

A

Earning master file

EXHIBIT A-14 Comparative Example-Version 3

N

2

Example Data Flow Diagram

Review time cards

Time 1 Cards

Example Flowchart

A = Alphabetic

N

2

Time 1 Cards

Factory Supervisor

Review Time Cards

Review Time Cards

Employee earnings records

Time card file (alpha)

Factory supervisor

Accounting payroll clerk

Time cards

Reviewed Time cards

Key in time cards

Record wages

A EmployeeEarning

master file