REQUIREMENTS CAPTURE 1 USE-CASE MODELING EXAMPLE A video sales and rental shop would like to computerize its management of sales and rental of its movie videos. As well, it would like to establish a presence on the Web and allow its customers to rent and buy videos via the Web. Below are the high-level requirements for a system that will manage the sale and rental of videos for the video shop: –The system must be able to keep track of which movie videos have been bought/rented and by whom. For videos bought, the system must record the quantity bought; for videos rented, the system must record which copy of the video has been rented and when it is due back. –The system must keep track of overdue rental videos and allow notices to be sent to customers who have videos overdue. –The video shop will have a customer membership option for an annual fee, which will entitle the member to discounts (10%) on video sales and rentals. –Members should be able to make reservations for movie video rentals either in person at the store, by telephone or via the Web. –A member can reserve at most five movie videos at any one time, but there is no limit on how many movie videos a member or nonmember can rent at any one time. –As an added feature, the video shop would like to allow customers (either members or nonmembers) to input, via the Web, mini-reviews (up to 100 words)

REQUIREMENTS CAPTURE 2 USE-CASE MODELING EXAMPLE (cont’d) and a rating (from 1, lowest, to 5, highest) of movies they have rented. These reviews should be anonymous if the customer so wishes (i.e., the customer can specify whether or not he wants his name to be made known when other customers browse the reviews). –The video shop maintains the following information about all customers (members or nonmembers): name, address, phone number, fax number, age, sex, and address. In addition, members are assigned a membership number by the video shop when they become members and a password, which allows them to access the members-only area of the video shop's web site, including accessing and changing their personal information. –Using the Web, customers should be able to buy and rent videos and browse the reviews entered by other customers. –Managers must be able to generate various reports on sales/rentals of videos. –Staff must be able to sell/rent videos from the store’s inventory and return rented videos to the store's inventory. –When selling or renting videos, staff must be able to look up customer information and determine whether the customer is a member. –An employee must be able to enter the basic information about a movie video (i.e., title, leading actor(s), director, producer, genre, synopsis, release year, running time, selling price, and rental price).

REQUIREMENTS CAPTURE 3 USE-CASE MODELING EXAMPLE — ANALYSIS We first analyze the functional requirements of the system and then present the use-case model. Note that for the purposes of producing the use-case model, we are only really interested in those functional requirements that provide something of value for some actor. – The system must be able to keep track of which movie videos have been bought/rented and by whom. functionality: Someone – bye a video Someone – rent a video – For videos bought, the system must record the quantity bought; for videos rented, the system must record which copy of the video has been rented and when it is due back. functionality: None (this is mainly domain model information) – The system must keep track of overdue rental videos and allow notices to be sent to customers who have videos overdue. functionality: Staff - produce rented video overdue notices

REQUIREMENTS CAPTURE 4 USE-CASE MODELING EXAMPLE — ANALYSIS – The video shop will have a customer membership option for an annual fee, which will entitle the member to discounts (10%) on video sales and rentals. functionality: Someone – enter member information. (The discount information is a nonfunctional requirement that affects the operation of some use cases such as buying and selling videos.) – Members should be able to make reservations for movie video rentals either in person at the store, by telephone or via the Web. functionality : Member - reserve a video Staff - reserve a video (Note that how the reservation is done is not important from a functional perspective.) – A member can reserve at most five movie videos at any one time, but there is no limit on how many movie videos a member or nonmember can rent at any one time. functionality: None. (This is a nonfunctional requirement—a domain model constraint.)

REQUIREMENTS CAPTURE 5 USE-CASE MODELING EXAMPLE — ANALYSIS – As an added feature, the video shop would like to allow customers (either members or nonmembers) to input, via the Web, mini-reviews (up to 100 words) and a rating (from 1, lowest, to 5, highest) of movies they have rented. functionality: Customer - enter a review for a video – These reviews should be anonymous if the customer so wishes (i.e., the customer can specify whether or not he wants his name to be made known when other customers browse the reviews). functionality: Elaborates preceding functional requirement – The video shop maintains the following information about all customers (members or nonmembers): name, address, phone number, fax number, age, sex, and address. functionality: Staff - enter/update customer/member information (Note that this requirement is implicitly stated in that someone (i.e., the staff) has to enter the customer/ member information into the system.) allow a member to update their personal information

REQUIREMENTS CAPTURE 6 USE-CASE MODELING EXAMPLE — ANALYSIS – In addition, members are assigned a membership number by the video shop when they become members and a password, which allows them to access the members-only area of the video shop's web site, including accessing and changing their personal information. – functionality: Memberf - update personal information – Using the Web, customers should be able to buy and rent videos and browse the reviews entered by other customers. functional requirement:Customer - buy a video Customer - rent a video Customer - browse video reviews – Managers must be able to generate various reports on sales/rentals of videos. functional requirement:Manager - generate reports

REQUIREMENTS CAPTURE 7 USE-CASE MODELING EXAMPLE — ANALYSIS Staff must be able to sell/rent videos from the store’s inventory and return rented videos to the store's inventory. functionality: Staff - buy (sell) a video Staff - rent a video Staff - return a rented video – When selling or renting videos, staff must be able to look up customer information and determine whether the customer is a member or not. functionality: Staff - lookup customer/member info – An employee must be able to enter the basic information about a movie video (i.e., title, leading actor(s), director, producer, genre, synopsis, release year, running time, selling price, and rental price). functionality: Staff - enter video information

REQUIREMENTS CAPTURE 8 USE-CASE MODELING EXAMPLE — SOLUTION Actors CustomerA customer is a person who uses the services of the video shop. A customer uses the system to buy or rent videos or enter or browse reviews via the Web. MemberA member is a kind of customer. In addition to what a customer can do, a member can also use the system to reserve videos and to access and change their personal information via the Web. StaffStaff are employees of the video shop. Staff use the system to sell and rent videos, reserve videos and enter and update video and customer/member information. ManagerA manager is a kind of staff. In addition to what staff can do, a manager can also generate various reports on sales and rentals of videos.

REQUIREMENTS CAPTURE 9 USE-CASE MODELING EXAMPLE — ANALYSIS Customer - buy a video Staff - sell (buy) a video Staff - lookup customer information Customer - rent a video Staff - rent a video Staff - return a rented video Staff - produce rented video overdue notices Staff - lookup customer information Customer - enter a review for a video Customer - browse video reviews Member - reserve a video Staff - reserve a video Staff - enter/update customer information Member - update their personal information Staff - enter video information Manager - generate reports Buy video Rent video Manage reviews Reserve video Manage customer info Manage video info Generate reports

REQUIREMENTS CAPTURE 10 USE-CASE MODELING EXAMPLE — SOLUTION Video Sales and Rentals System Generate reports Manage video info Buy video Rent video Manage reviews Manage customer info Reserve video Member Customer Manager Staff Buy video allows a customer (via the Web) or a staff (in the shop) to select a video and its quantity for purchase and staff to look up customer/member information. Rent video allows a customer (via the Web) or staff (in the shop) to select a video for rental, staff to return rented videos and to look up customer/member information, and the system to record which copy of a video has been rented, keep track of overdue videos, and produce notices for customers with overdue videos. Manage reviews allows a customer (via the Web) to browse video reviews or to input a review and rating for a selected video and to indicate whether the review is to be anonymous. Reserve video allows a member (via the Web) or a staff (in the shop) to reserve up to 5 videos at a time for rental. Manage customer info allows a member (via the Web) or a staff (in the shop) to enter or update personal customer/member information. Manage video info allows staff (in the shop) to enter video information. Generate reports allows a manager (in the shop) to generate various reports on sales and rentals of videos.

REQUIREMENTS CAPTURE 11 USE-CASE MODELING EXAMPLE: COMMON ERRORS System/devices/communication methods are not actors. (e.g., web, phone, etc. represent how something is done) Do not represent input/output devices as actors! Too large use cases. (e.g., Maintain video database) Too small use cases. Do not represent each operation as a use case! Reuse the same functionality for different actors. (e.g., Buy video  Customer, Staff)

REQUIREMENTS CAPTURE 12 USE-CASE MODELING EXAMPLE: COMMON ERRORS Do not represent nonfunctional requirements. (e.g., 10% discount) A use-case model is not a structure chart! A use-case model is not a domain model! A use-case model is not a work of art!