BTS330

Documenting Use Cases

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Documenting Use Cases A use case must have a specific

goal A use case will describe the

interaction between at least one actor and a computer system

Actor represents who is actually using the system

Use Case names begin with a verb

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Documenting Use Cases Shows the functionality that the

system will provide and which users (actors) will communicate with the system

Done using Rational Rose Documents the scope of the

system under development

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Documenting Use Cases Use Case Diagram

Actors are represented by a ‘stick’ figure

Use Cases are represented by an oval

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Documenting Use Cases

Sample Use Case Diagram

Process A Loan ApplicationStudentServicesClerk

View Status Of Loan

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Documenting Use Cases Do not confuse use cases with

functions i.e. invalid use cases:

Add Order Update Order Delete Order

Documenting Use Cases 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”

Documenting Use Cases 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 it’s goal

Documenting Use Cases 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

Documenting Use Cases 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

Documenting Use Cases Scenario is shown in a table format:

One column for Actor Describe what the actor does

One column for System Describe what the system does to respond

to the actors action 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: Video ID Title Cost

Subtotal:Taxes:Total:

Method OfPayment:

Amount Paid:

Credit Card No:Exp Date:

Add

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 Specification Sample use case specification for

Rent A Video

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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).

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Introduction to Use Cases 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

Rate Movie - X

Rating

Movie Title

Rating

Done

Movie TitleAdd

Screen & Report Design Guidelines for BTS330 Screen Design

Ensure all key data is reflected in screen mock up

Only include buttons that affect the path of the use case (i.e. probably don’t need to show ‘cancel’ button)

Screen & Report Design Guidelines for BTS330 Report Design

Ensure all key data is reflected in report design

Ensure that you show control breaks and summary data

Screen & Report Design Guidelines for BTS330 Mockup & Report Design

You can use any tool for mockups you wish; you can even hand draw them

Keep designs concise and simple – no fancy graphics

Mock ups are solely for the purpose of assisting in documenting your use case