Petrie

Petrie's Electronics Case, Chapter 7, Questions 1–5 and 7

CASE: PETRIE’S ELECTRONICS

Structuring Systems Requirements:

Conceptual Data Modeling

Jim Watanabe, manager of the “No Customer Escapes” project, and assistant director of IT for Petrie’s Electronics, was sitting in the company cafeteria. He had just finished his house salad and was about to go back to his office when Stephanie Welch sat down at his table. Jim had met Stephanie once, back when he started work at Petrie’s. He remembered she worked for the database administrator.

“Hi, Jim, remember me?” she asked.

“Sure, Stephanie, how are you? How are things in database land?”

“Can’t complain. Sanjay asked me to talk to you about the database needs for your new customer loyalty system.” Stephanie’s phone binged. She pulled it out of her oversize bag and looked at it. She started to text as she continued to talk to Jim. “How far along are you on your database requirements?”

That’s kinda rude, Jim thought. Oh well. “We are still in the early stages. I can send you a very preliminary E-R diagram we have [PE Figure 7-1], along with a description of the major entities.”

“OK, that will help. I suspect that you won’t have too many new entities to add to what’s already in the system,” Stephanie responded, still looking at her phone and still texting. She briefly looked up at Jim and smiled slightly before going back to texting. “Just send the E-R to me, and I’ll let you know if I have any questions.” She stood up, still looking at her phone. “Gotta go,” she said, and she walked away.

OK, Jim thought, I need to remember to send Stephanie the preliminary E-R we have. I should probably send her the entity descriptions too (PE Table 7-1), just in case. Jim stood up, carried his tray over to the recycling area of the cafeteria, and went back to his office.

When Jim got back to his office, Sanjay was waiting for him.

“I’ve got more information on those alternatives we talked about earlier,” Sanjay said. “I...