Knowledge Management: Writing Assignment 8 CRC

Writing Assignment 8: Object Oriented Thinking

Learning Objective:

For this assignment, you will develop a set of CRC cards that model the object oriented classes that would be needed to build a system to address the given scenario.

Background:

CRC stands for “Class-Responsibility-Collaborator”. CRC is the name of a brainstorming technique used by programmers and system engineers to explore the design of an object oriented system.  In a CRC exercise, you create index cards, with each card representing an object CLASS that would be needed to model the system

For each class, you then specify the RESPONSIBILITIES of that class, i.e. at a high level, what does the class do. These responsibilities would later become functions and methods of that class during development. Finally, if one class needs to interact with another class, they are listed as COLLABORATORS on each of their respective cards. This helps you understand the relationship between classes.

If you haven’t already, watch the tutorial on Lynda.com (remember to be logged in through http://lynda.psu.edu/ first before clicking on the link below):

Using CRC Cards – Tutorial:

Activities:

Place your answers into a word document and submit it to the drop box located in ANGEL’s “Writing Assignments” folder

Part I: For this assignment you will need to create a set of CRC cards for the scenario below. You can either list them here, or create them elsewhere first (using whatever technological means you feel most comfortable with) and then include them here. You can even create them by hand with index cards and scan in your collected set. Be creative!

Scenario:
A small used-car resale business wants has asked you to help them create their own website in the spirit of Autotrader.com or Carmax.com. (Note you have creative liberty here, if you want to limit the scope to just foreign cars, or domestic trucks, go right ahead).
On this website, customers are can search for vehicles based on price, make and model, and condition of the vehicle.  To use the website customers are required to login with their own unique ID.  Once logged in they can view the web page for each vehicle that contains an accident history report. Each vehicle on this website is listed by the owner or by a sales agent acting on the owner’s behalf. The owner or sales agent can upload pictures of the vehicle that are posted on the vehicles web page. The owner can only list 1 vehicle at a time, but a sales agent can list multiple vehicles. When the customer is interested in a vehicle they can submit a bid to the owner, who has 5 days to reject or accept the customers bid.

Part 2: Reflect on the CRC Card creating process.  Explain how you decided on your set of classes, their responsibilities, and collaborators.  What assumptions did you make in your card deck, and what extra information would you require to flesh out the requirements for this system?