1.
DFD: Simple Inventory System
(A Book-store Management System)
by:
Bharat V. Chawda
Computer Engineering Department,
BBIT, VVNagar, Gujarat, India
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2.
Overview
 Description
 High-level Functions
 Context Diagram
 Level 1 Diagram
 DFDs for Manage Book Data
 DFDs for Manage Sales
 DFDs for Manage Purchase
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3.
A Book-store Mng System
 Description
 Manages data regarding books, customers, employees,
suppliers and other relevant purchase & sale related
data.
 This system is managed by an Admin; has all the
administrative rights to perform required functionalities.
 Admin keeps track on the quantity of books. Whenever
required, he puts an order for purchasing new books to
supplier.
 To support this task, minimum quantity (or reorder
quantity) is managed for each book along with other
data.
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4.
A Book-store Mng System
 Description (cont.)
 Whenever supplier supplies order, stocks are updated
and bill-data related to supplier is stored.
 Related to each sale, a computerized bill is generated
for a customer. Based on selling, quantity is updated
(subtracted) for sold books automatically.
 Whenever required, admin can search data related to
some particular books, customers, employees or
suppliers.
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5.
High-level Functions
 High-level Functions
 1. Manage Book Data
 2. Manage Customer Data
 3. Manage Employee Data
 4. Manage Supplier Data
 5. Manage Sales
 6. Manage Purchase
 7. Login (for admin)
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6.
Context or Level 0 Diagram
 Concept:
 Main steps:
Identify where data is captured from: Source
Identify where data is distributed to: Destination
Describe the overall process
Map these out in a diagram using the correct
symbols
Link them with data flows that are labelled
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7.
Context or Level 0 Diagram
7
Book-store
Management
System
0
ADMIN
Search keyword
New Data/Modification
Detailed Data
Acknowledgement
Supplier Bill
CUSTOMER
Book Data, Qty
Customer Bill
SUPPLIER
Order
Supplier Bill
Order Data
User ID, Password Search Key Word
Detailed Data

8.
Level 1 Diagram
 Concept:
 Main steps:
 Identify and draw the processes that make up the Level 0
process: High level functions
 Allocate descriptions to these processes
 Lay out the sources/sinks and data flows from the
Level 0 diagram
 Draw in any data stores used in the process
 Link the new processes and data stores with named data
links: Data flows
[Note: It should be balanced. (What is balanced DFD?)]
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9.
Level 1 Diagram
9
1.0
Manage
Book Data
ADMIN D1 Book
Search Key Word
New Data/Modifications
Detailed Data
Acknowledgement
Data to be Stored/Deleted
Data to be Updated
Book Details
Similarly, represent other
processes
2.0
Manage
Customer
Data
3.0
Manage
Employee
Data
4.0
Manage
Supplier
Data
5.0
Manage
Sales
6.0
Manage
Purchase
7.0
Login
Note: For simplicity, details of all processes are not shown in this Level-1 diagram. Detailed diagrams of Process
5.0 and 6.0, ‘Manage Sales’ and ‘Manage Purchase’, are given later.

10.
Decomposition/Level ‘n’ Diagram
 Concept:
 Main steps:
 Identify and draw the processes that make up the Level
n-1 process
 Allocate descriptions to these processes
 Lay out the all the data flows from the Level n-1
diagram
 Draw in any data stores used in the process
 Link the new processes and data stores with named data
links: Data flows
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11.
Level 2 Diagram: Mng Book Data
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1.1
Add
Book
D1 Book
New Data Data to be Stored
1.2
Modify
Book
Modifications
Search Keywords
Acknowledgement
1.3
Remove
Book
Search Keyword
Acknowledgement
Book Details
1.4
Search
Book
Search Keyword
Detailed Data
Book Details
Book Details
Data to be Deleted
Data to be Updated
Acknowledgement

12.
Level 3 Diagram: Add Book
12
1.1.1
Read &
Validate
Data D1 Book
New Data Data to be
Stored
1.1.2
Insert
Data
Valid Data
1.1
Add
Book
New Data
D1 Book
Data to be Stored
Acknowledgement
Acknowledgement

13.
Level 3 Diagram: Modify Book
13
1.2.2
Read &
Validate
Modification
D1 Book
Modifications
1.2.3
Update
Data &
Acknow.
Valid
Modification
1.2.1
Search
Data
Search Keyword
Book Data
Data to be
Updated
Book Details
Acknowledgement
1.2
Modify
Book
Modifications
Search Keywords
Acknowledgement
D1 Book
Book Details
Data to be Updated

14.
Level 3 Diagram: Remove Book
14
1.3.2
Del Data &
Acknowledge
D1 Book
Acknowledgement
1.3.1
Search
Data
Search Keyword
Book Data
Data to be Deleted
Book Details
1.3
Remove
Book
Search Keyword
Acknowledgement
D1 Book
Book Details
Data to be Deleted

15.
Level 1 Diagram: Manage Sales
15
D5 CBill
5.0
Manage
Sales
CUSTOMER
D1 Book
Book Data + Quantity
Customer Bill
Book Details
D2 Customer
Customer Details
Stock Update Data
Customer Bill Data

16.
Level 2 Diagram: Manage Sales
16
5.1
Receive
Order
Book Data
Quantity
Book Data
5.2
Verify
Order
Received
Order
D1 Book
5.3
Prepare
Bill
Verified
Order
Stock Update Data
D2 Customer
Customer Details
D5 CBill
Customer Bill Data
Customer
Bill
Book
Data

17.
Level 3 Diagram: Prepare Bill
17
5.3.1
Get
Customer
Details
Customer
Data
Verified Order
D2 Customer
Customer
Details
D5 CBill
5.3.3
Generate
Bill
Data
Customer
Bill Data
5.3.4
Print
Customer
Bill
Customer Bill
5.3.5
Update
Stock
Customer
Bill Data
D1 Book
5.3.2
Get
Book
Details
Book
Data
Book Details
Stock
Update Data
Customer
Bill Data

18.
Level 3 Diagram: Prepare Bill (ii)
18
5.3.1
Get
Customer
Details
Customer
Data
Verified Order
Customer Bill
Details
D2 Customer
Customer
Details
D5 CBill
Customer
Bill Data
5.3.3
Generate
Bill
Data
5.3.4
Store
Bill
Data
Customer
Bill Data 5.3.5
Print
Customer
Bill
Customer Bill
5.3.6
Update
Stock
Customer
Bill Data
D1 Book
5.3.2
Get
Book
Details
Book
Data
Book Details
Stock
Update Data

19.
Level 1 Diagram: Manage Purchase
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6.0
Manage
Purchase
SUPPLIER D1 Book
Order
Supplier Bill
Book Details
D4 Supplier
Supplier Details
Stock Update Data
Supplier Bill Data
ADMIN
Supplier Bill
Order Data
D7 SBill
Supplier Order Data
D6 SOrder

20.
Level 2 Diagram: Manage Purchase
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21.
Thank-U…!!!
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