Question and Answer: 1. [6 points] What is a DFD? Why do system analysts use DFDs? 2. [6 points] List three types of service models for cloud computing. Explain the differences among the service models. 3. [15 points] Suppose you are developing a system for a retail clothing store in a mall, list relevant data flows, data stores, processes, and sources/sinks. Draw a context diagram and a level-0 diagram (with more than 4 processes and 2 data stores) that represent the selling system at the store. Explain why you chose certain elements as processes versus sources/sinks. 4. [15 points] In one company, the rules for buying personal computers specify that if the purchase is over $15,000, it has to go out for bid, and the Request for Proposals (RFP) must be approved by the Purchasing department. If the purchase is under $15,000, the personal computers can simply be bought from any approved vendor; however, the Purchase Order must still be approved by the Purchasing department. If the purchase goes out for bid, there must be at least three proposals received for the bid. If not, the RFP must go out again. If there are still not enough proposals, then the process can continue with the one or two vendors that have submitted proposals. The winner of the bid must be on an approved list of vendors for the company and must not have any violations against them for affirmative action or environmental matters. At this point, if the proposal is complete, the Purchasing department can issue a Purchase Order. Draw a decision table to represent the logic in this process. Notice the similarities between the text in this question and the format of your answer. 5. [8 points] If you were going to develop a computer-based tool to help an analyst interview user and quickly and easily create and edit E-R diagrams, what type of tool would you build? What features would it have? How would it work?