EXAMPLE DATA FLOW
DIAGRAM
Generate Point Redemption Coupons
• Assume your assignment as an analyst is to take the 3.0
process and break it into smaller sub-processes
This figure from the text has an error, all processes MUST be numbered
Data flows, sources, and
sinks outside the boundary
of the process will remain the
same as we decompose the
process into subprocesses
Additional Information
• The ‘Generate point redemption coupons’ process has
several sub-processes
• The process ‘Separate into Categories’ takes the ‘Customer Activities’
data and classifies purchases as either ‘TV purchase or ‘Computer
purchase’ or ‘Other purchase’
• A TV purchase is checked to see if it is a TV suitable for a wall
mounting, if so an instant coupon is created at the cash register and
given to the customer
• A computer purchase causes an instant coupon to be generated for the
customer to purchase additional memory – a file matching computer
memory to computers is kept by Petrie Electronics
• All other sales go to a process that groups them by product group and
updates the ‘Customer Activity Records’
Begin by including sources and sinks that cross the boundary
Customer
Activity
Records
Customer
Next add the sub-processes
Customer
Activity
Records
3.2 If wall
mounted, create
coupon
3.1 Separate
into categories
3.3 Create coupon
for memory
3.4 Create totals
by product group
Customer
Next add any required data stores
Customer
Activity
Records
3.2 If wall
mounted, create
coupon
3.1 Separate
into categories
3.3 Create coupon
for memory
Memory Specifications
3.4 Create totals
by product group
Customer
Then add data flows and label them
(remember that the data flows across the boundary cannot change)
Customer
Activity
Records
TV
3.2 If wall
mounted, create
coupon
Coupons
Customer Activities
3.1 Separate
into categories
Computer
All other activities
3.3 Create coupon
Coupons
for memory
Memory specifications
Memory Specifications
Coupon Information
3.4 Create totals
by product group
Customer
Check for errors
Customer
Activity
Records
TV
3.2 If wall
mounted, create
coupon
Coupons
Customer Activities
3.1 Separate
into categories
Computer
All other activities
3.3 Create coupon
Coupons
for memory
Memory specifications
Memory Specifications
Coupon Information
3.4 Create totals
by product group
Customer