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. “, 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 [ ], 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 proba
bly send her the entity descriptions too ( ), 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 had one of my employees gather some data on how the alternatives might satisfy our needs.” (See the descriptions of the alternatives in .) Sanjay handed Jim a short report. “The matrix shows the requirements and constraints for each alternative and makes it relatively easy to compare them.” (See .) “The matrix favors the XRA CRM system,” Jim said, after looking over the report. “It looks like their proposal meets our requirements the best, but the Nova group’s proposal does the best job with the constraints.” “Yes, but just barely,” Sanjay said. “There is only a five-point difference between XRA and Nova, so they are pretty comparable when it comes to constraints. But I think the XRA system has a pretty clear advantage in meeting our requirements.” “XRA seems to be pretty highly rated in your matrix in terms of all of the requirements. You have them ranked better than the other two proposals for implementation, scalability, and vendor support,” Jim said. “The ‘5’ you gave them for proven performance is one of the few ‘5s’ you have in your whole matrix.” “That’s because they are one of the best companies in the industry to work with,” Sanjay responded, “Their reputation is stellar.”