Hardcopy due at 11:00 am on Tuesday, September 12, 2017. (Words must be typed, not handwritten. ER diagram may be hand-written, clearly and tidily.)
Your design must satisfy the first two criteria.
Satisfying the last four criteria is optional. However, for each of the last four criteria that your design does not satisfy, you must include in your writeup a clear, convincing and compelling explanation of why you think it is "unnatural" for your application (i.e., explain why multi-way relationships, specialization / generalization, and weak entity sets do not make sense for your application).
Your relationships must also have a variety of multiplicities (one-to-one, one-to-many, many-to-many).
To summarize, your design MUST be "rich" in all these goodies we discussed in class! It is expected that the ER diagrams will satisfy at least four out of the six criteria.
Don't forget to underline key attributes, to specify integrity constraints (cardinality and participation), specify any domain-specific constraints, and to thick-border any weak sets and their connections. It is possible that you may make your design more complicated than necessary; if you have more than eight entity sets, you should probably prune them.
What to turn in: Neatly drawn hard-copy of ER design, plus accompanying explanations and discussions of constraints. Identify your group by your project title and the team members.
Required but not graded: Include one sentence per group member summarizing each group member's contribution to Project Part 2. These sentences will be required in all project parts. They are not for part of any student grades. They will be used to monitor group dynamics, and to try to intercede in troubled groups (if any) before troubles get out of hand.
VERY VERY Strongly Recommended: Send one or more members of your group to my office hours a few days before the deadline, to show me your current ER diagram draft and get fast feedback. (I have office hours most days of the week. Or make an appointment. Showing me the ER diagram before the deadline is important. You will be required to have a complete and correct ER diagram to work with for Part 3. If there are any flaws in your ER diagram, you will have to both revise and correct Part 2 and complete Part 3 based on your revisions before the Part 3 deadline. So you want the flaws to be very small and easy to fix!)
Common Mistakes in Design:
In general, an aspect of your ER diagram created to satisfy criteria 2.4 or 2.5 will not also count towards 2.1 or 2.2. Do not double-count when deciding if your ER diagram satisfies the assignment requirements. (Bring a draft of your ER diagram to the instructor and let the instructor help you figure out if it satisfies requirements!)
"Set B inherits from Set A. Set A participates in a many-many relationship with Set C. But Set B does not have a many-many relationship to Set C, it has no relationship to C."
This kind of reasoning is flawed. If Set B inherits from (specializes) Set A, it gets everything from A, so you do not have the right to make exceptions to this rule. This probably means that this is not a real example of inheritance; it may have been cooked up.
Hint for the future: After you have completed this assignment, start thinking about how you would translate your ER diagram into relations.