INTRODUCTIONINTRODUCTION

Documentation explains how AISs operate Vital part Example: Describe tasks for recording data,

procedures that users must perform to operate computer applications, logical and physical flow of accounting data through the system

WHY DOCUMENTATION VITAL?WHY DOCUMENTATION VITAL?

1. Depicting how system works

2. Training users

3. Designing new system

4. Controlling system development and maintenance costs – save time & money

5. Standardizing communications with others

6. Auditing AISs

7. Documenting business processes

Types of TechniquesTypes of Techniques

1 Data flow diagrams1 Context diagram2 System flowcharts3 Document flowcharts4 Program flowcharts

5. Decision Table

Data Flow Diagrams (DFD)Data Flow Diagrams (DFD) graphically describes the flow of data within an

organization. Helps users to conceptualize the relationship between

data items, inputs, process, outputs and data storage It is used to document existing systems and to plan

and design new ones. There is no ideal way to develop a DFD. A data flow diagram (DFD) is composed of the

following four basic elements:1 Data sources and destinations2 Data flows3 Transformation processes4 Data stores

Guidelines for Drawing a DFDGuidelines for Drawing a DFD

1. Understand the system.

2. Ignore certain aspects of the system.

3. Determine system boundaries.

4. Develop a context diagram.

5. Identify data flows.

6. Group data flows.

7. Identify transformation processes.

8. Group transformation processes.

Cont..Cont..

9. Identify all files or data stores.

10. Identify all data sources and destinations.

11. Name all DFD elements.

12. Subdivide the DFD.

13. Give each process a sequential number.

14. Repeat the process.

15. Prepare a final copy.

Data Flow Diagram SymbolsData Flow Diagram Symbols

Data Source and destinations

Data Flows

Internal entity (physical DFD) or Transformation Processes (logical DFD)

Data Stores

Data Flow Diagram SymbolsData Flow Diagram Symbols A data source or data destination symbol on the DFD

represents an organization or individual that sends or receives data that they system uses or produces.

A data flow represents the flow of data between processes, data stores and data sources and destinations.

A transformation process represents the transformations of data.

A data store is a temporary or permanent repository of data.

A data dictionary contains description of all the elements, stores, and flows in a system.

DFD example processDFD example process

Data source

(A)

Process(C)

Data flow (B)

Data flow (D)

Data flow (E)

Data destination

(J)

Data store (H)

Process(F)

Data flow (G)

Data flow (I)

Data destination

(K)

DFD Customer’s Payment ProcessDFD Customer’s Payment Process

Client(A)

Processpayment

(C)

Client paid(B)

RemittanceData

(D)

Deposit (E)

Bank(J)

A/c Receivables (H)

Update Receivables

(F)

(G)

Receivables Info(I)

CreditManager

(K)

Data Flow DiagramsData Flow Diagrams

Data flow diagrams are subdivided into successively lower levels in order to provide increasing amounts of detail.

CONTEXT DIAGRAMSCONTEXT DIAGRAMS The highest-level DFD is referred to as a context diagram. Shows major data flows in and out of a system Detailed inflow data normally hidden Shows a subsystem as a process - interrelationship of

subsystems and their relationship to main system Level zero data flow diagram – when each of the

processed involves is referred to on the diagram by number 1.0, 2.0, 3.0 etc.

Decomposition of a data flow diagram – expanding each process with a more detailed data flow diagram exp –1.1, 1.2,1.3

Eg: What is the context diagram for payroll processing?

Example Context DiagramExample Context Diagram

Payrollprocessing

system

Departments

Humanresources

Time cards

Employee data

Governmentagencies

Employees

Bank

Management

Tax reports and payments

Employee paychecks

Payroll check

Payroll report

FLOWCHARTFLOWCHART A diagrammatical representation of physical

operating process of a system An analytical technique used to describe some aspect

of an information system in a clear, concise, and logical manner.

Flowcharts use a standard set of symbols to pictorially describe transaction-processing procedures.

Flowcharting symbols can be divided into the following four categories:1 Input/output symbols2 Processing symbols3 Storage symbols4 Flow and miscellaneous symbols

Some Input Output SymbolsSome Input Output Symbols

Document

Online keying operation

Display

Input/output; Journal/ledger

Symbol Name

Punch card

Multiple Document

Paper or Permanent file of manual documents (letter inside symbol indicates file sequence order)A= alphabeticallyN=numericallyD=chronologically

Envelop for mailing or distribution bills/ cheques, etc

Symbol Name

1

32

A

Processing SymbolsProcessing Symbols

Manual operations

Computer processing

Auxiliary operation / offline process

Symbol Name

Storage SymbolsStorage Symbols

Magnetic disk

Magnetic tape

Symbol Name

Online storage ie: a CD- ROM file

Flow and Miscellaneous SymbolsFlow and Miscellaneous Symbols

On-page connector

Off-page connector

Terminal = start/stop

Decision

Document or processing flowSymbol Name

Miscellaneous SymbolsMiscellaneous Symbols

Symbol Name

Telecommunications link

Annotation symbol for comments or further descriptions

Flow of physical goods (ie: inventory shipment)

1. Document Flowcharts1. Document Flowcharts illustrates the flow of documents and information

between areas of responsibility within an organization. Traces the physical flow of documents through an

organization. Constructing a document flowchart begins by

identifying the different departments or groups that handle the documents of a particular system.

A document flowchart is particularly useful in analyzing the adequacy of control procedures. Auditors and accountants may use document flowcharts when analyzing a current system for weaknesses in controls and reports.

Flowcharts that describe and evaluate internal controls are often referred to as internal control flowcharts.

Requesting Department Central Supplies Department

21Goods

requisition form (GRF)

A

File

A

1Goods requisition

form (GRF)

2. System Flowcharts2. System Flowcharts Describe logical flows of data and processing steps in an

AIS that is the relationship among the input, processing, and output of an AIS.

Each processing phase of a system flowchart usually involves preparing one or more control reports.

These flowcharts illustrate an electronic job stream of data through processing phases of an AIS, and therefore illustrate audit trails. begins by identifying both the inputs that enter the system and their origins.

The input is followed by the processing portion of the flowchart.

The resulting new information is the output component. System flowcharts are an important tool of system

analysis, design, and evaluation.

Computer using payroll

program

Payroll master file

Time cards and payroll changes

Pay cheques & Report

Illustration of system flowchartIllustration of system flowchart

Enter document into computer via keyboard, edit input, record input

User queries the computer Update sequential data store Preparation and Later Manual Reconciliation of

Control Totals Key And Key Verify Inputs Enter document into computer using a scanner Enter document into computer using scanner &

manual keying

3. Program Flowcharts3. Program Flowcharts describes the specific logic to perform a process shown

on a systems flowchart. A flow line connects the symbols and indicates the

sequence of operations. The processing symbol represents a data movement or

arithmetic calculation. The input/output symbol represents either reading of

input or writing of output. The decision symbol represents a comparison of one

or more variables and the transfer of flow to alternative logic paths.

All points where the flow begins or ends are represented by the terminal symbol.

What are Program Flowcharts?What are Program Flowcharts?

Input data

If a condition is met No

Yes

Perform calculation

Update record

Flowchart for Processing Credit OrdersFlowchart for Processing Credit Orders

Entersalesorder

Approvedfor credit?

Rejectorder

Inventoryavailable?

Back-order

Fill order Stop

Start

No

Yes

Yes

No

Guidelines Preparing FlowchartGuidelines Preparing Flowchart

i. Based on your table of entities and activities: identify entities to be flowcharted i.e. department/person or

external parties. Also identify process involved, data and documents storage

used and data flow within the system.

ii. When several entities need to be flowcharted: divides the flowchart into several column and label each column

with the respective entity. It is recommended to create column for internal entities ONLY. No specific column will be provided for external entities such as

customer, bank, supplier and etc. Terminator/terminal symbol will be used to represent external

entity.

iii. Flowchart only the normal flow of operations. • Indicate exceptional activities by using annotation symbols.

iv. Give flowchart a clear beginning and ending. • Indicate where each document originated and show the final

disposition of all documents.

• There will be no loose end in flowchart.

v. Put document number on top right corner of the document for multiple documents.

• The number should accompany the symbol as it passed through the system.

21

vi. Flowchart columns should be laid out so that the flowchart activities flow from left to right,

• BUT you should locate columns so as to minimize crossed lines and connectors.

vii. Flowchart logic should flow from top to bottom and from left to right.

• For clarity, put arrows on all flow lines.

viii. Each manual processing activities should have an input and output (sandwich principle).

• Do not directly connect two documents except when moving document from one entity to another.

• Input/Output can be either document or storage

Input

Process

Output

Input

Process

Output

Input

Process

Output

ix. Use on-page connector to avoid flow lines that go all over the page.

A

x. Keep the flowchart on one page. • If you can’t, use multiple pages and connect the pages with off-

page connectors. • Do not glue, tape, staple, or otherwise extend your flowchart to

get it one one page. • Use off-page connector to move from one page to another

A, 2 A, 1

xi. Within each column, there must be at least one manual process, keying operation, or data store between documents.

• That is, do not directly connect documents within the same column.

xii. When crossing organizational lines (one column to another),

• show a document at both ends of the flow line unless the connection is so short that the intent is unambiguous.

xiii. Documents or reports printed in data processing (DP) should be shown in the DP column first.

• You can then show the document or report going to the destination unit.

xiii. Documents or reports printed by a centralized computer facility on equipment located in another organizational unit (warehouse, shipping dept.)

• should not be shown within the computer facility.

xv. Processing within an organizational unit on devices such as a PC or computerized cash register should be shown within the unit or as a separate column next to that unit, but not in the central computer facility column.

xvi. Sequential processing steps (computerized or manual) with no delay between them can be shown as one process or as a sequence of processes.

xvii. The only way into a computer data storage unit is through a computer processing rectangle.

xviii. A manual process is not needed to show the sending of a document.

• The sending of the document should be apparent from the movement of the document itself.

xix. Do not use a manual process to file a document. • Just show the document going in to a file.

xx. If the sequence of records in a document file is important:

• include the letter ‘A’ for alphabetical order, ‘N’ for Numerical (number) order or ‘C’/’D’ for chronological order/sort by date.

Use arrowhead to indicate dataflow.

1. emphasize the flow of data and what is happening in a system

2. represents the logical flow of data

3. make use of only four symbols

4. used primarily to document existing systems.

DFDs vs FlowchartsDFDs vs Flowcharts1. emphasizes the flow of

documents or records containing data.

2. represents physical flow of data.

3. use many symbols and thus can show more detail

4. primarily used in the design of new systems and do not concern themselves with the physical devices used to process, store, and transform data.

Adv & Disadv of flow chartsAdv & Disadv of flow charts

Advantages A flow chart enables any system, especially a complex system,

to be represented in an easily understandable manner The overall picture of the system is easily seen The relationship among different parts of the system is

highlighted.

Disadvantages The creation of a flow chart can be time consuming Numerous symbols can cause confusion A process may not be completely presentable using symbols

DECISION TABLEDECISION TABLE

A table of conditions and processing tasks that indicates what action to take for each possibility

Alternative to program flowchart; when computer program involves large number of conditions & subsequent action, program flowchart tends to be large and complex

Illustration – interest on accountIllustration – interest on account

A bank pays interest to its depositors at rate of 5% per year. Accounts of less RM5 are not paid interest. Accounts of RM1,000 or more that have been with the bank for more than a year get paid normal 5% plus bonus 0.5%

RULES

  1 2 3 4

conditions

condition stuba/c bal less than RM5 Y N N N

Condition entriesa/c bal less than RM1,000 * Y * N

a/c 1 year old or less * * Y N

actions

action stubpay no interest X

action entriespay 5% interest X X

pay 5.5% interest       X

Adv & Disadv Decision tableAdv & Disadv Decision table Advantage

1. Summarize processing tasks with complex conditions into compact, easily understood format

2. Increase understandability3. Reduce possibility of omitting important process4. More accurate & complete processing financial data

Disadvantage1. Do not show the order in which program test data

condition or processing action take place2. Need knowledge of documentation technique beyond

flowchart3. Extra work to prepare and may cost ineffective

SOFTWARE TOOLSSOFTWARE TOOLS1. Microsoft Word and Excel

2. CASE tools – front end and back end