1. Example Data Flow Diagram

2. Generate Point Redemption Coupons
Assume your assignment as an analyst is to take the 3.0 process and break it into smaller sub-processes

3. 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

4. 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’

5. Begin by including sources and sinks that cross the boundary
Customer Activity Records
Customer

6. 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

7. 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

8. Customer Activity Records
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
3.3 Create coupon for memory
Coupons
Memory specifications
All other activities
Memory Specifications
Coupon Information
3.4 Create totals by product group
Customer

9. Check for errors

10. Customer Activity Records
3.2 If wall mounted, create coupon TV
Coupons
Customer Activities
3.1 Separate into categories
Computer
3.3 Create coupon for memory
Coupons
Memory specifications
All other activities
Memory Specifications
Coupon Information
3.4 Create totals by product group
Customer