Process Modeling

254 PART III ANALYSIS

"e!tua PETRIE ELECT RONICS Chapter 7: Structuring System Process Requirements

Jim and Sanjay chatted in Jim's office while they waited for Sally to anive.

"Good work on researching those alternatives," Jim said. "Thanks," replied Sanjay. "There are a lot of alternatives

out there. 1 think we found the best three, considering what we are able to pay."

Just then Sally walked in. "Sorry I'm late. Things are getting really busy in Marketing right now. I've been put- ting out fires all morning."

Sally sat down at the table across from Jim. "I understand," Jim said. "But to stay on schedule, we

need to start focusing on the specifics of what we want our system to do . Remember when you wanted more de- tails on what the system would do? Well, now we start to spend some serious energy on getting that done."

"Awesome," replied Sally, as she pulled a Red Bull out of her oversized bag and popped it open.

"I've got a list here of four core functions the system must perform," said Sanjay, pulling copies of a list from a folder on the table (PE Table 7-1). "Let's look at these."

After reviewing the list Sanjay had given them, Jim said, "Nice job, Sanjay. But we need to put this in graphical for- mat, so that everyone can see what the inputs and outputs are for each function and how they are related to each other. We also need to see how the new system fits in with our existing data sources. We need ... . "

"Some data flow diagrams, " Sanjay interrupted. "Exactly," said Jim. "They are already done," replied Sanjay, handing dia-

grams to both Jim and Sally. "I've already created a first draft of the context diagram (PE Figure 7-1) and a level-l diagram (PE Figure 7-2). You can see how I've defmed the boundaries of our system, and I've included our existing product and marketing databases."

"What can 1 say?" Jim said. "Again, a nice job on your part. These diagrams are both good places for us to start. Let's get copies of all of this to the team."

"I'll b e right back," Sally said, standing up . "I need to get some coffee."

PE TABLE 7-1 four (are functions 01 Petrie's (ustomer Loyally Syslem

Function

Record customer activities

Send promotions

Generate point redemption coupons

Generate customer reports

Description

When a customer makes a purchase, the transaction must be recorded in the customer loyalty system, as the rewards the system generates ore driven by purchases . Similarly, when a customer uses Q coupon generated by the system , it must also be recorded , so that the customer activity records can be updated 10 show that the coupon has been used and is now invalid.

Data cbouf customer activities provide information about what types of products customers tend to buy and in what quantities . This information helps determine what soles promotion mcte ri als are best targeted at what customers . Customers who buy lots of video gomes should receive promotions about games, game platforms, and HD TVs, for example .

Data about customer activities is used to generate coupons for future purchases. Those coupons must be made available to customers, either as paper caupons sent in the mail , or they should be made available online, in the customer's private occaunt area . Once created, the customer activity database needs to be updated to show the creation of the coupon . The loyalty points needed to create the coupon must be deducted from the customer's total points .

From lime 10 lime, either in Ihemail ar electron ically, customers need to be send account reports that show their recant purchases, the coupans they have been issued that have nat yet been redeemed, and the tolal points they hove amassed from their purchases .

CHAPTER 7 STRUCTURING SYSTEM PROCESS REQUIREMENTS 255

PE FIGURE 7-1 Context diagram

I l. Custome,

"--_P_U_,C_h_as_e_s-il.,r: o-c-u-st-omer Reports ; =J' ..- Tailored Promotions

J Escapes t----------~Il. Customer Coupons 1 System Coupons

I---'----'~

r-- !

Customer

Coupons

Purchases

(-- Record

I Customer I Activities

,---- ,

Transactions I Customer Activity Records ,

C I A r ,,,---------.., ustomer ctlvdles ~lcoup~n Info Marketing

Database

PE FIGURE 7-2 level·1 DFD

Case Questions

Promotions i Send L Promotions

1. Are the DFDs in PE Figures 7-1 and 7-2 balanced? Show that they are, or are not. If they are not balanced, how can they be fixed?

2. Decompose each of the core processes in PE Figure 7-2 and draw a new DFD for each core process.

3. Has the team overlooked any core processes in the sys- tem that should be in PE Table 7-1 and PE Figure 7-2? What would they be? Add them to PE Table 7-1 and PE Figure 7-2.

Customer Activities ;- CA ' . I Generate Point ustomer ctlVlty

Redemption Coupons

Coupons I I Generate

....... _R_e.:-p_ort_s _______ ..;l Customer Reports '--<-_.1

t Product Info

~ ___ l __ _ ,

I Product

Database

~ -~~-....

Info

4. Redesign PE Figures 7-1 and 7-2 so that they are clearer and more efficient and more comprehensive.

5. Why is it important for the team to create DFDs if they are not going to write the actual system code themselves?

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