Skill Test: Sushi Restaurant Model

In a previous post, I discussed the use of fictitious situations to use as a discussion platform to "test drive" the skills and thought processes of a potential candidate during an interview. The example below details the aspects of a Sushi-Bar Restaurant Model.

• Discussion Topic:  Sushi Bar Restaurant Model
• Context:
• Margo has a successful sushi-bar restaurant business. However, it is not automated. She would like to introduce automation to how her business can interact with customers. She would like a system that:
• allows the sushi chef to plan the sushi menu for a given period (daily, weekly, bi-weekly) basis of the different dishes that the restaurant will serve on a given day. A dish is comprised of a number of ingredients. Margo and her staff chef decide how many servings of a particular dish they will serve on a given day. Based on that serving count, they will create the shopping list for that period. Every dish type that has no meat will have a fixed price (at the discretion of  the Margo or the chef). Every meat-based dish will have a variable price (only Margo can set the price on each day). 
• allows Margo and / or chef to set the price for each dish. There are 5 price categories for a serving of a dish: top-shelf, premium, yum-yum, muy-rico, and not-too-bad. Each price category will be served on a saucer plate color-coded for the price: red, yellow, orange, blue, and green (respectively)
• When a dish is built and apportioned into servings that dish must be served on the plate of the corresponding color that was determined during the menu generation process
• Allows a customer to check-in by using either the mini-kiosk located at the table or by interacting with the system via a phone app
• Allows the customer to place their order of drinks
• As the customer consumes the serving on a sushi plate the system keeps tally of the color of the plate and how many plates the customer has consumed 
• Allows the customer to check out, pay for the meal (based on consumption) and add any gratuity. On Sundays, gratuity is automatically added to the meal if they consume more than 10 servings of a given dish. They amount of the gratuity is set at 10%, but the system should allow Margo to configure it when needed.
• Feel free to edit this to your needs and set up aspects of the problem to cater for the type of skill you are looking for
• What to ask the candidate
• System Analysis and Design Track
• please construct a UML conceptual model diagram that shows all the aspects of the house in the "context" portion above.
• please construct a UML class diagram that represents the home described above
• please construct a UML system sequence diagram that illustrates any of the interactions listed above that you consider interesting
• please construct a UML use case diagram based on the description above
• Would make any modifications to the system behaviors described by Margo? How would you go about suggesting any modifications to Margo and the chef?
• Data Modeling Track
• please, construct an entity relationship diagram (ERD) that can be used to represent the home described above
• What to look for
• assuming that you know UML, compare and contrast what the candidate came up with and what you would have come up with
• pay extra attention to the assumptions that the candidate made. If they do not mention any assumptions, please, simply ask them: What assumptions did you make as you were thinking about this problem?
• Use this opportunity to ask questions and experiment / explore what it would be like to work with this individual