DNSC-SAD 2018: Chapter 9

CASE STUDY New Century Health Clinic New Century Health Clinic offers preventive medicine and traditional medical care. In your role as an IT consultant, you will help New Century develop a new information system. Background:   After completing the user interface, input, and output design for the new information system at New Century, you will consider data design issues. Begin by studying the DFDs and object-oriented diagrams you prepared previously and the rest of the documentation from the systems analysis phase. Perform the following tasks: Assignments 1. Create an initial entity-relationship diagram for the New Century Health Clinic system. 2. Normalize your table designs. 3. If you identified any new entities during normalization, create a final entity-relationship diagram for the system.  4. Write a memo for your documentation file that contains your recommendation about whether a file processing or a database environm...

Western Wear Outfitters Situation:   Western Wear is a mail-order firm that offers an extensive selection of casual clothing for men and women. Western Wear plans to launch a new Web site, and the company wants to develop a new set of product codes. Currently, 650 different products exist, with the possibility of adding more in the future. Many products come in various sizes, styles, and colors. The marketing manager asked you to develop an individualized product code that can identify a specific item and its characteristics. Your initial reaction is that it can be done, but the code might be fairly complex. Back in your office, you give the matter some thought. 1.        Design a code scheme that will meet the marketing manager’s stated requirements. Some firms use a straight numeric sequence code, because it is simple and can be assigned automatically by the system. Other firms choose a significant digit code that indicat...

Mayville Public Library  Situation:  Mayville is a rural village with a population of 900. Until now, Mayville was served by a bookmobile from a larger town. The Mayville Village Council has authorized funds for a small public library, and you have volunteered to set up an information system for the library. Assume that the library will have multiple copies of certain books. 1. Draw an ERD for the Mayville library system. 2. Indicate cardinality. 3. Identify all fields you plan to include in the tables. Students should be imaginative and suggest field attributes that would  be appropriate and typical in a library information system that Mayville Public Library would use. 4. Create 3NF table designs.

Puppy Palace Situation: Puppy Palace works with TV and movie producers who need dogs that can perform special tricks, such as headstands, somersaults, ladder climbs, and various dog-andpony tricks. Puppy Palace has about 16 dogs and a list of 50 tricks from which to choose. Each dog can perform one or more tricks, and many tricks can be performed by more than one dog. When a dog learns a new trick, the trainer assigns a skill level. Some customers insist on using dogs that score a 10, which is the highest skill level. As an IT consultant, you have been asked to suggest 3NF table designs. You are fairly certain that a M:N relationship exists between dogs and tricks. 1. Draw an ERD for the Puppy Palace information system. 2. Indicate cardinality. 3. Identify all fields you plan to include in the dogs and tricks tables. For example, in the dogs table, you might want breed, size, age, name, and so on. In the tricks table, you might want the trick name and des...

Pick and Shovel Construction Company Situation:        Pick and Shovel Construction Company is a multi state building contractor  specializing in medium-priced town homes. C. T. Scott, the owner, is in your office for  the third time today to see how the new relational database project is coming along.  Unfortunately, someone mentioned to C. T. that the delay had something to do with  achieving normalization. “Why is all this normalization stuff so important?” he asks. “The old system worked OK most of the time, and now you are telling me that we need all these special rules. Why is this necessary?” 1. How should you respond to C. T.? Write him a brief memo with your views. Normalization: Normalizing a database reduces its size and prevents data duplication. It ensures that each piece of data is stored only once. Normalization is important to develop system performance and accuracy.  Normalization splits huge am...