We-b-Videos  
 

 

Design Goals

Performance
        Response Time: Fast response time and high throughput are needed to service customers at peek hours. They will be essential when the system is eventually upgraded to the web to reduce online wait times and allow multiple customers to engage in transactions.
  Throughput:
Dependability
  Robustness: The system must be able to work around mistyped passwords, outdated customer id's, and other invalid user input.
  Reliablity: Maintaining accurate information about inventory, customers, movies, and rental transactions is essential to meeting the specified functional requirements.
  Availability: This system must be able to handle multiple customers in the store (e.g. There may be two or three lines of customers at peek hours). This will be essential when the system is upgraded to the web since unavailability translates directly into loss of commerce.
  Security: In anticipation of the eventual move to the web, security must be in place to protect customer information and databases from theft and vandalism.
Cost
  Development: We must try to remain within the client's given budget.
  Maintenance: Since we already know how We-b-Videos future plans, we must minimize the amount resources necessary to upgrade to the web.
Maintenance
  Extensibility: Since video stores tend offer new services over time (e.g. Start with renting cassettes and then offer video games and DVDs), the system should be able to accommodate the new functionality and classes to implement new services. Also, once the system has been "webified" more services become possible, such as linking to movie reviews and emailing notification of new releases.
  Portability: Though the current in-store system need not be portable, when upgraded to the web the system must be able to function on multiple platforms.
  Modifiability: The system must be modifiable, again, to facilitate the move to the web. The web- based system will have no use for return videos and pay late fees functionality.
  Adaptability: The goal is especially important because one of the main requirements for the system is that it must be adaptable to the new application domain of the web.
  Readability: Code must be readable to aid in extensibility and portability.
  Traceability: The code must be taceable to aid in extensibility, portability, and adaptability.
End User
  Utility: The system must support the basic functions of the video store; rent, return, search, pay late fees.
  Usability: Allow general public to use the system on both in store terminals and the web.
 
Contents  Subsystem Definitions
Hosted by www.Geocities.ws

1