SYS366 Documenting Use Cases

Use Case Specifications For each use case in a use case diagram, need to describe, in detail, how the use case works = “a use case description or specification”

Use Case Specification A use case specification describes the interaction between the actor and the system – it describes the steps, in sequential order, that a use case must do to fulfill a goal

Use Case Specification A use case specification must include: Who the actors are and how many of them are interacting with the system at any point in time What data is used and how All success and failure logic

Use Case Specification A use case can have many paths through which it’s goals are accomplished – each path is know as a scenario Each scenario can represent success logic or failure logic A scenario is ONE PATH through a use case

Use Case Specification Scenario is shown in a table format: One column for Actor Identify the actors who are involved in the scenario One column for Scenario Description Describe, in order, the steps that are done to complete the scenario Written as a dialog between the actor and the system Described using the Casual Use Case Specification Template

User Interface Design The process of designing the overall sequences that users follow to interact with an information system The sequence in which information is displayed to and obtained from the user Understanding how the user will interact with the system

User Interface Design Whether a success or failure logic, interface will be the same Need to visualize the steps through the use case Example: Rent A Video

Use Case Specification Interface for Rent A Video use case might look like: Rent Video - X Customer Id: Name: Phone #: Outstanding Balance: Address: Video ID Title Cost Video Id: Add Method Of Payment: Subtotal: Taxes: Total: Amount Paid: Credit Card No: Exp Date:

Use Case Specification Ie. Rent A Video use case Some possible scenarios could be: Pay by credit card (normal logic) Pay by debit card (normal logic) Pay by cash (normal logic) Credit card invalid (exception logic)

Use Case Descriptions Sample Use case description for Rent A Video

Introduction to Use Cases Carl’s OutDoors is a small business that rents various types of equipment for outdoor trips. Equipment such as camping equipment and canoes are rented. They also sell equipment for camping and canoeing and they organize outdoor adventure trips. Carl’s business has become very successful and he is having trouble keeping up with the growth. He needs to upgrade the system he currently has to handle the growing number of customers. Carl has asked you to help with the rental part of his business. Customers want to rent either camping equipment or canoes. When they are finished, the customers want to return the equipment. On occasion it is necessary for a customer to exchange the equipment they’ve rented. This could be for a variety of reasons. Such as, the equipment is defective (i.e. a tent might have a hole in it causing it to leak; or a canoe isn’t big enough for the canoeists and their equipment). As new equipment is received each season, Carl makes old equipment available for sale. Usually it is a final sale but customers are allowed to return equipment that is defective (i.e. a tent might have a hole in it causing it to leak; or a canoe that might have a hole in it as well causing it to let water seep in).

Introduction to Use Cases Rent Equipment Return Rental Equipment Exchange Rental Equipment Process A Sale Make Equipment Available For Sale Return Equipment

Use Case Descriptions Sample Use case description for Make Equipment Available For Sale Make Equipment Available For Sale - X Equipment Id: Equipment Name: Equip ID Name Cost For Sale? y/n Done

Use Case Descriptions Sample Use case description for Rate Movie - X Movie Title Add Rating Movie Title Rating Done