Data Flow Diagramming
Solutions to
In-Class Exercises
In-Class Exercise: Precision Tools
Precision Tools sells a line of high-quality
woodworking tools. When customers place orders on
the company’s Web site, the system checks to see if
the items are in stock, issues a status message to the
customer, and generates a shipping order to the
warehouse, which fills the order. When the order is
shipped, the customer is billed. The system also
produces various reports.
1. Draw a Context Diagram for the order system.
2. Draw a Level-0 DFD for the order system.
Precision Tools Context Diagram
IN-STOCK
REQUEST
ORDER
WAREHOUSE
CUSTOMER
PAYMENT
0
STATUS
MESSAGE
SHIPPING ORDER
ORDER
SYSTEM
SHIPPING CONFIRMATION
INVOICE
INVENTORY
REPORTS
ACCOUNTING
DEPARTMENT
SHIPPING CONFIRMATION
1
Precision
Tools
Level-0
Diagram
IN-STOCK REQUEST
ORDER
CHECK
STATUS
STATUS
DATA
STATUS
MESSAGE
CUSTOMER
WAREHOUSE
ORDER DATA
D1
PENDING
ORDERS
2
INVOICE
ORDER
DATA
PAYMENT
ISSUE
MESSAGES
5
3
MANAGE
ACCOUNTS
RECEIVABLE
GENERATE
SHIPPING
ORDER
ACCOUNTING
DATA
D3
SHIPPING
ORDER
ACCOUNTS
RECEIVABLE
DATA
ACCOUNTS
RECEIVABLE DATA
4
ORDER DATA
PRODUCE
REPORTS
INVENTORY
REPORTS
ACCOUNTING
DEPARTMENT
In-Class Exercise: Evergreen Nurseries
• Sells plants and gardening supplies wholesale
• Sales representative takes customer order via phone
–
–
–
–
verifies customer’s credit
determines if items are in stock
notifies customer of product(s) availability
informs customer of special discounts and total cost
• Order is processed
–
–
–
–
customer account updated
product inventory adjusted
ordered items pulled from stock and packed
order shipped to customer with packing slip
• Billing
– monthly billing statement sent to customer
– customer has 30 days to remit payment
• Monthly reports produced for manager
Context Diagram for the
Evergreen Nurseries Order System
Order
Wholesale
Customer
Credit
Approval / Disapproval
Nursery
Manager
Product
Availability
Order Discounts
& Cost
Shipment Packing Slip
Monthly
Statement
Payment
on Account
Order
System
Monthly
Reports
Level-0 DFD for the
Evergreen Nurseries Order System
Shipment Packing Slip
Product Availability
Order
Wholesale
Customer
Order Discounts & Cost
Credit Approval /
Disapproval
Customer
Charge
Monthly
Statement
Payment
on Account
Current
Balance
1.0
Receive
Order
Placed
Order
Credit
Check
Availability
of Item
2.0
Update
Customer
Account
3.0
Adjust
Inventory
Quantity
Check
Updated
Balance
D2
Filled
Order
Sold
Item
Product
D3
Order
Credit Status
D1
Customer
Order Data
Product
Data
4.0
Customer Data
Generate
Reports
Monthly
Reports
Nursery
Manager
Level-1 DFD for the Evergreen Nurseries
Order System Update Customer Account Process
2.1
Wholesale
Customer
Payment
on Account
Apply
Customer
Transaction
1.0
Customer
Charge
Updated
Balance
2.2
Monthly
Statement
Create
Monthly
Statement
Current
Balance
D1
Customer
Receive
Order